A type of protein that is part of the immune system. Antibodies recognize and attach themselves to infectious organisms and foreign materials so they can be removed from the body.

a protein found in the blood or bodily fluids that tags, destroys or neutralizes bacteria, viruses and other harmful toxins found in the immune system.

Protective substance formed in body against a specific infection.

A protein substance, developed in response to an antigen, that destroys or neutralizes bacteria, viruses or other harmful toxins. This antigen/antibody reaction forms the basis of immunity (see also p24 antigen and autoimmune response).

a protein (made by white blood cells) that defends against invading foreign agents, such as bacteria, as part of the immune system response.

A type of protein made by certain white blood cells in response to a foreign substance (antigen). Antibodies bind to the antigen and either destroy the foreign substance directly or make it easier for the body to do so.

Proteins produced by B-lymphocytes that normally serve to recognize and bind to foreign substances that enter the body like infections and environmental chemicals. Antibodies are the foot soldiers of the body's immune system which is designed to protect itself from foreign invasion.

a type of protein called an immunoglobulin found in the blood that is produced by immune cells in response to the presence of a foreign particle (antigen). Antibodies are specific to each different type of foreign particle. Primary : first antibody used in an immunoassay to detect the foreign particle; in this case, we are testing to see if the serum from the patients contains primary antibodies to SLE. Secondary antibody: the second antibody used in an immunoassay that detects the primary antibody. Note, this antibody must be made in a different species (rabbit, donkey, horse) than the primary antibody, in order to recognize the primary antibody as "foreign". In this case, we are using HRP-tagged rabbit anti-human antibodies as our secondary antibody.

A protein, produced in response to a foreign substance in the immune system.

Antibody Protein that binds specifically to a particular substance – its antigen. Produced by B-lymphocytes in response to infection or immunization.

specialized proteins made by white blood cells that help to neutralize foreign proteins, toxins or microrganisms and thus help the body defend itself against infection (see also monoclonal antibodies).

A protein produced by B-cells that specifically recognises and binds onto foreign matter (antigen)

a protein produced by the immune system cells that binds to antigens so other elements of the immune system can attack and destroy or remove the antigen.

A Y-shaped protein that is secreted into the blood or lymph to fight against bacteria, viruses and other foreign particles.

A protein molecule produced by cells of the immune system in response to an antigen (foreign body), such as a virus or bacteria. Antibodies circulate in the blood to protect against infection. The presence of antibodies can indicate current or past exposure to a pathogen (see 'pathogen').

a type of protein that is part of the immune system. Antibodies are designed to fight off specific factors that may cause sickness or disease. The mother’s antibodies are given to her baby through breast milk. This helps strengthen the baby’s immune system.

A substance which reacts only to the antigen that is responsible for its production in the cells or to a closely related antigen.

Protein produced by humans and higher animals in response to the presence of another protein, termed an antigen. The interaction of the antigen and the antibody can cause certain human health problems, like allergies or autoimmune diseases.

An antibody is a blood protein that the body makes in response to contact with a particular foreign substance (an antigen). The antibody combines with the substance to make it harmless. Antibodies are triggered in response to a variety of substances such as bacteria, pollen grains, and foreign blood cells. The antibody response is the basis of both immunity and allergy, and for the body’s rejection of organs in transplantation.

complex protein-based molecule produced by B-lymphocytes that binds to and helps eliminate foreign and infections agents

A large protein made in response to a foreign antigen (generally a protein).

A component of the body's immune system. An antibody is a Y-shaped protein that binds specifically to a foreign substance (antigen) and marks it for destruction and/or removal. Antibodies can work in several ways, depending on the nature of the antigen.

Protein produced by the body, in response to a foreign substance, to fight the invading organism

Glycoprotein produced in response to an antigen. Antibodies have the ability to combine with the antigen that stimulated their production.

Proteins that are made by the body in response to an antigen. Antibodies act specifically against the antigen (idlergen) that provoked their production. Antigen: A substance that reacts with antibodies. In an allergic individual the antigen is called an allergen and includes pollen and dust mites. Antihistamine: A drug that inhibits the action of histamines, which are released during the allergic reaction. Histamines smooth muscles and dilate capillaries causing allergic symptoms.

anti-, against + bio, life] (n) in the body's immune system, a molecule that is responsible for recognizing and marking an antigen for destruction by the white blood cells

a protein secreted by activated plasma cells, which evolve from B-cells, in response to stimulation by an antigen.

a protein produced by the immune system to attack bacteria, viruses or other invading disease producing agents. Each antibody has a molecular structure that exactly fits the structure of each foreign body (antigen) like a key and a lock. Antibodies are carried in the blood. It is also common to add antibodies to treat specific disease antigens if we lack immunities to them (vaccination).

One of millions of proteins, produced by the immune system, that specifically recognizes a foreign substance and initiates its removal from the body.

proteins produced by the body that in response to a specific substance, such as bacteria or antigen, that forms the basis of immunity

A molecule used by the immune system to fight invading organisms that cause infection.

An inducible immunoglobulin protein that is produced by the B lymphocytes of the immune system. It recognizes and binds to a specific antigen molecule of a foreign substance introduced into the organism. Upon binding to corresponding antigens, the antibodies set in motion a process to eliminate the antigens.

(AN tih BOD ee): Molecule produced by B cells that circulates in the bloodstream and neutralizes antigens.

A protein produced by some of the body s white blood cells that helps fight infection.

the body's natural defenders against foreign invaders by neutralizing or destroying them through various mechanisms. Also referred to as immunoglobulins.

"Defense protein that recognizes invading microbes and helps to kill them."

A chemical produced by specialized lymphocytes when that lymphocyte encounters a foreign substance. The antibody identifies the invader as being foreign. The antibody is part of the immune system that helps rid the body of foreign substances that are usually a virus or bacteria.

Protein that fights infections.

a protein which is produced by the lymphoid tissue to fight against antigens. All antibodies are immunoglobulins.

A protein (immunoglobulin) produced by a B-cell that binds to a specific foreign antigen in the blood or body fluids. This leads to attack by the immune system.

Protein produced by B lymphocytes in response to a foreign molecule or invading organism. Often binds to the foreign molecule or cell extremely tightly, thereby inactivating it or marking it for destruction by phagocytosis, or complement-induced lysis.

a protein substance produced in the blood in response to foreign substances that marks them for destruction by other elements of the immune system.

protein produced by the immune system as a defense against an invading or "foreign" material or substance (an antigen); for example, when you get a cold, your body produces antibodies to the cold virus

A protein substance formed by certain white blood cells in your body to help defend it against disease.

protein that targets foreign substances in the body which are destroyed by the immune system

A protein made by the body's immune system to defend the body against a foreign substance like a virus, bacterium or other foreign body, most often a foreign protein. Rarely, the body’s immune system may mistakenly make antibodies against itself. This is an abnormal or autoimmune response.

a protein created by B-cells that binds to an antigen or prevents antigens from entering healthy cells

A protein of the immune system, produced in response to an antigen (a foreign, often disease-causing, substance).

a protein (also called immunoglobulin) produced by the body in response to a molecule that is recognized as foreign (i.e. an antigen* or, in the case of allergy, an allergen*). The antibodies responsible for allergic reactions are of the immunoglobulin E (IgE) class.

A protein substance which helps defend the body against infections due to viruses, bacteria, and other foreign organisms.

A protein produced in the body in response to contact with an antigen. An antibody neutralizes the antigen and creates an immunity to that antigen. An integral part of the immune system.– See also Antigen

A protein (modified type of blood serum) developed or synthesized by lymphoid tissue of the body in response to an antigen. Each antigen elicits production of a specific antibody.

A protein present in serum or other body fluid that combines specifically with antigen; an immunoglobulin (Lecture: Acquired Immunity, 2/14/02)

A protein made by the body's immune system to fight foreign substances, such as germs or a new organ.

A protein substance produced by the immune system in response to a foreign organism.

a protein made by your body that destroys foreign matter

A protein produced by the body's immune system that recognizes and helps fight infections and other foreign substances in the body. When your body is infected with a particular strain of influenza, the immune system makes antibodies that are specific to that strain.

A protein produced by B-lymphocytes in response to, and interacting specifically with, an antigen. This antigen-antibody reaction forms the basis of immunity, and is exploited in various immunoassays. (Also see IgG.).

A protein produced and secreted by a B cell in response to an antigen. Each antibody recognizes and binds to a particular antigen and may as a result of the binding inactivate or destroy it, or allow other components of the immune system to do so.

protein molecule formed by the immune system which reacts specifically with the antigen that induced its synthesis. All antibodies are immune globulins.

Defensive protein molecule which detects foreign materials such as bacteria and binds to them, so making them harmless

Protein molecule produced by the immune system (an immunoglobulin molecule) which can bind specifically to the molecule (antigen or hapten) which induced its synthesis. RT antigen, hapten, immunoglobulin.

Antibodies are proteins in the blood made by the immune system to help the body fight disease. Vaccines stimulate the body to make antibodies to specific infectious agents eg hepatitis B.

a specific substance produced by the body's immune system in response to a particular infection.

Substance formed by the body's immune system as a reaction to foreign antigens or proteins.

a protein made by the body to fight foreign substances known as antigens. Each antigen has a specific antibody.

A protein produced by the immune system in response to a specific foreign substance (antigen) which attempts to eliminate the foreign substance from the body.

A substance that fights only with the antigen that caused it's formation

A defense protein that binds to foreign molecules to allow elimination of the foreign molecule.

A protein produced by cells of the immune system which specifically recognises a target molecule known as an antigen. A key component of the body's immune defence mechanism to foreign agents

A protein molecule produced by the immune system in response to a foreign body, such as virus or a transplanted organ. Since antibodies fight the transplanted organ and try to reject it, recipients are required to take anti-rejection (immunosuppressive) drugs.

A substance in the body that fights disease and foreign substances.

A protein substance produced by certain white blood cells in response to a foreign substance (antigen), such as a bacterium or toxin. Each antibody can bind only to a specific antigen.

A substance produced by the body which destroys foreign matter e.g. bacteria.

Large, Y-shaped proteins produced by the immune system that attach to pathogens and other foreign molecules, tagging them for destruction. There are five classes of antibodies, each with different characteristics and roles in the immune system. In proteomic research, antibodies engineered to react to a specific protein or peptide are an essential tool for identifying proteins, and are commonly used in several techniques. See also Microarray, Western Blot.

A substance produced in the blood by the body's immune system to defend against other harmful substances.

A protective protein produced by the body which reacts against foreign substances (antigens). Antibodies act in various ways in order to counter the effects of antigens.

A specific antibody which can be produced in large quantities by cells originating from one cell line (a clone). This cell line is obtained by the fusion of an antibody-producing cell (lymphocyte) with a rapidly growing cell. All the monoclonal antibodies produced by a hybrid cell are identical.

A protein which is part of the body's immune system. These are produced within the body in response to unfamiliar material and help the body defend itself.

Protein produced by a plasma cell that is generated in reaction to a foreign protein (antigen), thus producing an immunity against that protein; also known as an immunoglobulin.

a protein produced by the immune system in response to an antigen. The antibody binds to the antigen and enables the immune response to destroy the antigen.

a molecule tailor-made by the immune system to lock onto and destroy specific foreign substances, such as allergens

A type of serum protein (globulin) synthesized by white blood cells of the lymphoid type in response to an antigenic stimulus, the role of antibody being to inactivate or render harmless the infading the antigen.

A protein that is produced in response to an antigen (often another protein from a virus or bacterium). It is able to attach tightly to the antigen. ( see also)

proteins produced by the immune system in response to antigens; an important component of the immune system.

A specialized protein produced by B-Cells used by the immune system to fight foreign invaders or disease.

A protein produced by the immune system which attaches to an antigen. (The antigen is usually a complex biochemical compound that is from outside the organism. Usually antigens are present on infectious pathogens, although they may also be on non-infectious substances such as pollen.) When an antigen from outside is present in the body, it stimulates the production of a specific antibody that will combine with it, usually enabling it to be eliminated. There are many thousands of different types of antibodies.

a protein, produced by B-cells. Antibodies bind specifically to foreign material, thereby helping the immune system to destroy it.

Proteins produced by the body's immune system in response to specific antigens.

A protein made by the body in response to the presence of a foreign body, like a virus or bacteria. Antibodies fight against foreign bodies by attaching to them.

A protein produced by the immune system that helps the body fight a particular disease or develop an immunity to it. The human body is capable of generating more than a trillion different antibodies.

(Also called immunoglobulin) An infection-fighting protein in blood or secretory fluids that recognizes, neutralizes, and helps destroy pathogenic microorganisms (e.g., bacteria, viruses) or toxins. Antibodies are made and secreted by B-lymphocytes in response to stimulation by antigens. Generally, each antibody binds only to the specific antigen that stimulated its production.

a protein substance produced in the blood or tissues that destroy or weaken germs

a protein (immunoglobulin) formed by the body to fight infections. Antibodies are produced by plasma cells (mature B cells) in response to antigens. Antibodies are released by the plasma cells into the circulatory system as exact mirror images of a specific antigen.

a complex molecule produced by lymph tissue in response to the presence of an antigen; antibodies neutralize the effect of the antigen.

A specific protein produced by the body in response to a challenge from a foreign substance known as an antigen. Men and women may produce antibodies for example to sperm.

A protein that works to defend the body against bacterial and viral infections.

A component of the immune system evoked by the stimulus of a foreign substance (antigen) which reacts specifically with the antigen.

protein produced by certain immune cells that recognizes and binds to foreign proteins, leading to the destruction of those proteins.

A protein produced by the immune system in the body that travels in the blood and helps the body to fight infection.

special substances that attack and destroy foreign bodies. Antibodies will attack antigens that are different from yours.

Substance produced by the immune system to fight invading organisms, such as viruses

A substance produced in the blood to counter toxins and invading organisms.

A substance in the blood formed in response to invading disease agents such as viruses, fungi, bacteria, and parasites. Usually antibodies defend the body against invading disease agents, however, the HIV antibody does not give such protection.

a substance prepared in the body for the purpose of withstanding infection by viruses, bacteria and other organisms.

A specific substance (immunoglobulin) produced by specialized blood cells (plasma cells) as a reaction to an antigen for the purpose of host defense. Antibodies are blood proteins that are produced in response to a foreign substance or antigen.

An antigen-specific receptor, also called an immunoglobulin, made by B-lymphocytes. Antibodies are a critical component of the immune system that circulate in the blood and bind to foreign antigens and tumor cells, marking them for destruction by immune proteins or other immune cells. Monoclonal antibodies (mAb) are laboratory-produced antibodies that can locate and bind to cancer cells wherever they are in the body. Each one recognizes a different protein on certain cancer cells. They are used in cancer detection or therapy, and can be administered alone or used to deliver drugs, toxins or radioactive material directly to a tumor.

Molecule that defends the body against bacteria, viruses, or other foreign bodies (antigens); also called immunoglobulins.

a protein that is produced by certain cells in the immune system in response to another substance (an antigen), and that reacts specifically with that substance.

a specific protein produced by the body's white blood cells to kill a specific foreign body; for example, antibodies are produced against the different kinds of colds, flu and HIV.

Protein secreted by the immune system, which interacts with a specific invading antigen in an immune response. The presence of antibodies is used s a test for infection by a virus.

A protein made by white blood cells to fight a specific foreign protein.

is a protein which is a natural part of the immune system produced by a specialized cell to recognize and neutralize foreign substances.

An immunoglobulin that recognizes some portion of an antigen molecule. The antibody contains a species-specific Fc region and antigen-specific Fab portion.

A special type of protein made by the body''''s immune system. It disarms or destroys a specific foreign agent (called an antigen) when it appears in the body.

a specialized protein produced by the immune system that helps destroy disease-causing organisms. An antibody is a component of humoral immunity. Antibodies can be effective defenders against both bacteria and viruses. An antibody must be made specifically for each pathogen.

A special protein made by white blood cells in the immune system. These proteins move through the blood stream looking for and attaching to foreign materials—such as viruses and bacteria—in order to neutralize them.

a protein structure of the immune system which tags material for destruction by white blood cells.

a protein that helps the body fight foreign substances (antigens) in the body, such as bacteria, fungi and viruses.

A protein produced by the white blood cells (leukocytes) to battle foreign substances, such as bacteria, that enter the body. The body produces millions of different antibodies, each equipped to target and destroy a specific antigen.

A molecule produced by lymphocytes in response to stimulation by an antigen. Antibodies bind to antigens, causing the cells bearing the antigens to clump together. These clumps are then destroyed by other blood cells. See also: Antigen See also: Prostate-Specific-Antigen test

A protein manufactured by lymphocytes to neutralise an antigen (foreign protein) in the body. The formation of antibodies against a foreign protein is part of the body's normal defence system

A protein produced by the body and used to fight against invading foreign substances called antigens. Each type of antibody works against a specific antigen.

specialized serum proteins produced by white blood cells (B lymphocytes) in response to an immense number of different antigens to which an animal has been exposed.

A specialized serum protein (immunoglobulin or gamma globulin) produced by B lymphocytes in the blood in response to an exposure to foreign proteins ("antigens"). The antibodies specifically bind to the antigens that induced the immune response. Antibodies help defend the body against infectious agents such as bacteria, viruses or parasites.

specialized serum protein produced by B lymphocytes in response to an exposure to foreign proteins or modified natural proteins (both act as antigens). The antibodies produced specifically bind to the antigens that induced the immune response. These are also called immunoglobulins or gamma globulins.

a substance produced in the blood capable of counteracting pathogens.

a protein that is manufactured by lymphocytes to neutralize or destroy an antigen or foreign protein. Many types of antibodies are protective against infection. Rarely, antibodies are produced against tissues in the body resulting in illness (autoimmune disease).

A substance made by white blood cells that helps fight infection in response to a specific antigen.

A special protein produced by the body that is capable of recognizing another protein (referred to as an antigen). Antibodies are normally produced by the body in response to infection. The antibody is able to recognize the surface of the invading bacteria or virus, therefore marking it for destruction by the immune system. Technological advances have allowed antibodies to be used as therapeutics for the treatment of a variety of diseases, including cancers. In the case of cancer, the antibody is designed to recognize a protein found on the surface of cancer cells, therefore causing an immune reaction which eliminates them.

Any of various proteins produced by the blood in response to the presence of an antigen. It can bind to the antigen, allowing it to be recognized by the body as friend or foe.

A three-lobed globulin containing two short and two long chains of protein, found in blood and other body fluids, that can be incited by the presence of antigen; it has a destructive influence on the antigen that stimulated its formation , thus producing immunity. B-cells bombard viral particles with antibodies until they find one which works, and then manufacture large quantities of the effective antibody and release it into the blood . They also retain a memory of these antibodies - if the virus ever attempts to reinfect the body, B-cells quickly manufacture the remembered antibody and wipe it out.

Any of the complex glycoproteins produced by B lymphocytes in response to the presence of an antigen. A single antibody molecule consists of four polypeptide chains, two light chains and two heavy chains, all of which are joined by disulfide bonds. The heavy chains form the compliment binding site, and the light and heavy chains form the antigen binding site. Antibodies, all of which are immunoglobulins, may combine with specific antigens to destroy or control them, providing protection against most common infections. Almost all antibodies except natural antibodies (e.g., antibodies to different blood types) are created by B cells linking with a foreign antigen on the surface of an invading organism. Antibodies neutralize or destroy antigens in several ways. They can initiate lysis of the antigen by activating the complement system, neutralizing toxins released by bacteria, opsonizing the antigen or forming a complex to stimulate phagocytosis, promoting antigen clumping (agglutination), or preventing the antigen from adhering to host cells.

A protein produced by the immune system in response to an antigen. The antigen can be an infectious agent for example Newcastle disease virus.

A specific protein substance produced by the body's immune (defence) system in response to an antigen (foreign substance), for example bacteria which are rendered harmless.

A protein that counteracts the effects of something foreign to your body. Antibodies are manufactured by white blood cells called lymphocytes and are formed when you have a virus, like a cold or flu, an infection from a bacteria, or are exposed to something you are allergic to, such as dust mites, foods, pollens. Although many types of antibodies are protective, too many of some types can lead to illness.

Any of a large number of proteins, produced by specialized B-cells ( plasma cells) after exposure to an antigen, that act exclusively against that antigen in an immune response. (Also called immunoglobulin.) Examples include Immunoglobulin G (IgG), IgM, IgA, IgD and IgE.

A protein produced by the immune system in response to an antigen, often a virus or bacterium

A protein made by the immune system that is specific to an antigen. When an antibody detects this antigen in the body, it will start an immune response to rid the body of the antigen.

These are immunologic proteins, usually made from immunoglobulins, that are capable of binding to, and rendering inactive, foreign substances that have entered the skin envelope and have been deemed dangerous. They may be synthesized anew in the presence of a previously encountered substance (antigen); they may be present in small amounts at all times in the bloodstream; or they may be present in the tissues in a more primitive form designed to react to a broad spectrum of potential antigens. The latter may be responsible for some allergies.

A substance produced by the immune system to fight infections and foreign substances. Antibodies are produced in response to specific antigens.

A protein produced by blood plasma cells that binds specifically to substances that the body recognizes as foreign. Inhibitors that occur in response to replacement therapies for hemophilia are antibodies to Factor VIII.

A substance in the blood that forms when disease agents such as viruses, bacteria, fungi and parasites invade the body. Although antibodies usually defend the body against invading disease agents, HIV antibodies, over time, give no such protection.

Any of a number of proteins produced in response to an antigen that acts specifically against that antigen in an immune response

immunoglobulin molecule that interacts with the antigen that elicited its production

A substance secreted by the immune system to help fight infection.

Any of the body globulins that combine specifically with antigens and neutralize toxins, agglutinate bacteria or cells, and precipitate soluble antigens.

a substance in blood that destroys infective agents.

an-tee-BOD-ee Protein that B cells secrete that recognizes and binds to foreign antigens, disabling them or signaling other cells to do so. 790

A protein made by a plasma cell (mature B cell) that protects the body against foreign invaders like bacteria and viruses.

A protein produced by the white blood cells (leukocytes) to battle foreign substances that enter the body, such as bacteria.

A type of glycoprotein molecule, also called immunoglobulin (ig), produced by B lymphocytes that binds antigens, often with a high degree of specificity and affinity. The basic structural unit of an antibody is composed of two identical heavy chains and two identical light chains. N-terminal variable regions of the heavy and light chains form the antigen-binding sites, whereas the C-terminal constant regions of the heavy chains functionally interacts with other molecules of the immune system. Every individual has millions of different antibodies, each with a unique antigen-binding site. Secreted antibodies perform various effector functions, including neutralizing antigens, activating complement, and promoting leukocyte-dependent destruction of microbes (1).

A protein produced by white blood cells in response to an antigen. It is part of the immune response.

A type of serum protein that is produced by the body in response to invasion by foreign proteins, e.g. viruses or bacteria, called antigens. Antibodies assist the body in removing or destroying foreign antigens.

a protein that specifically recognises and binds a target molecule known as an antigen.

A blood protein produced in response to an antigen (any substance capable of producing antibodies) in the body. Antibodies bind to antigens, often produced by disease, and help the body fight against them. Antibodies can help the body to develop immunity to a disease.

Protein synthesized by lymphocytes to help eliminate a foreign material (antigen) from the body.

A substance in the blood formed in response to invading disease agents such as viruses, bacteria, fungi, and parasites. Antibodies defend the body against invading disease agents. Molecules in the blood or secretory fluids that tag, destroy, or neutralize. They are members of a class of proteins known as immunoglobulins, which are produced and secreted by B-lymphocytes (B-cells).

Any of a large variety of proteins normally present in the body or produced in response to an antigen which it neutralizes, thus producing an immune response

A large protein that defends the body against antigens by binding to them so they can be destroyed. They're also called immunoglobulins, and are made by the immune system's B lymphocytes

A molecule in the body that reacts with a specific substance that caused it to be formed. People with allergies produce large amounts of antibodies to the particular allergens they're allergic to.

A protein that is present in the blood, made by cells of the immune system to fight infection. Some antibodies are a normal part of the body's immune defense, and others are made in response to a foreign substance. Scientists can make antibodies that target specific types of cells in the body.

A protein complex that specifically interacts with an antigen.

Molecule produced by B-lymphocytes (plasma cells) which serves to opsonize bacteria (prepare them for phagocytosis) and neutralize viruses and toxins. Known also as an immunoglobulin, the protein includes a specific sequence of amino acids allowing it to interact only with the antigen that provoked its production. Antigen Any substance capable of producing an immune response, for example the production of an antibody. APC A tumor suppressor gene named after the inherited condition adenomatous polyposis coli (see FAP) and the first commonly occurring tumor suppressor gene to be identified through the study of a rare familial type of cancer. Also stands for antigen presenting cell.

A glycoprotein released by a B-lymphocyte in response to a foreign compound (antigen). The antibody has the capacity for high specific binding to the antigen.

A substance produced in the blood of an individual which is capable of producing a specific immunity to a specific germ or virus.

Small disease-fighting proteins produced by certain types of cells called 'B cells.' The proteins are made in response to 'foreign' particles such as bacteria or viruses. These antibodies bind with certain proteins (antigens) on foreign particles like bacteria, to help inactivate them. See also antigen.

an immunoglobulin molecule with a specific amino acid sequence by which it interacts only with the antigen that induced its formation or antigen that is very similar to it.

A protein produced by the immune system in response to the presence of a specific antigen and that binds to the antigen. When antibodies bind to corresponding antigens, they usually set in motion a process to eliminate the antigens. A monoclonal antibody is produced by cells created through the fusion of an antibody-producing cell (such as a B-lymphocyte) with an immortalized cell. This process is accomplished in a laboratory and produces hybrid cells that express properties of both parent cells. The cells are all identical since they derive from a single cell and therefore are called “monoclonal.” These cells produce large amounts of a specific antibody that binds to a specific antigen.

compound made by acquired immune response designed to eliminate specific molecule, recognized as “not- self,” by lymphocytes

a molecule produced by the body to defend itself against bacteria, viruses, and other foreign substances

A protein in the blood that fights against an invading foreign agent (antigen). Each antibody works against a particular antigen.

Any of a large family of glycoprotein molecules known as immunoglobulins. There are normally present in the body and are produced by B-lymphocytes in response to an antigen which it neutralizes thereby creating an immune response. Their name of immunoglobulin is derived from the fact that they migrate with globular proteins when antibody-containing serum is placed in an electric field.

An immunoglobulin, a specialized immune protein , produced because of the introduction of an antigen into the body, and which possesses the remarkable ability to combine with the very antigen that triggered its production. See the entire definition of Antibody

A substance formed by the body to help defend it against infection.

A protein produced by the body's immune system in response to a foreign substance (antigen). Our bodies fight off an infection by producing antibodies. An antibody reacts specifically with the antigen that triggered its formation and its function is to inactivate the antigen.

A protein molecule capable of combining specifically with an antigen.

A disease-fighting protein in the blood created by the B cells of the immune system, and also known as immunoglobulin. Antibodies coat, mark for immune destruction, or render harmless, foreign particles like bacteria, viruses, or harmful toxins. Antibodies also tag infected cells, making them vulnerable to attack by the immune system. Each antibody attaches itself to a single, specific chemical sequence on an antigen.

a special protein produced by the body's immune system that recognizes and helps fight infectious agents and other foreign substances that invade the body.

A serum protein consisting of soluble molecules that are part of the body's immune system; they are produced in response to and bind to substances, usually foreign, known as antigens.

A part of the body's defense mechanism formed in response to a foreign antigen. Antibodies attack infectious agents and toxic substances.

Pronunciation: (AN-tih-BAH-dee) A type of protein made by lymphocytes (a type of white blood cell) in response to an antigen (foreign substance). Each antibody can bind to only one specific antigen. The purpose of this binding is to help destroy the antigen. Antibodies can work in several ways, depending on the nature of the antigen. Some antibodies destroy antigens directly. Others make it easier for white blood cells to destroy the antigen.

A protein found in the bloodstream to fight infection.

an infection-fighting protein molecule in the blood or secretory fluids that tag, destroy, or neutralize bacteria, viruses, or other harmful toxins. Antibodies, known generally as immunoglobulins, are made and secreted by B lymphocytes in response to stimulation by antigens. An antibody is specific to an antigen.

compounds (proteins) produced by our body's immune system (see antigen). The immune system is a group of cells in our bodies that fight diseases.

A protein produced in the body in response to invasion by foreign material (antigen).

A substance formed by the immune system that defends the body against antigens (bacteria, viruses, toxins) or tumors.

a protein, produced by plasma cells, which binds specifically to an antigen. Antibodies play a major role in the immune response.

An immunoglobulin which is present in the blood serum naturally or may develop as a result of an antigenic stimulus (such as a foreign cellular material). It attaches itself to these specific foreign substances, alerting the body to their presence.

a substance that inhibits infection

A protein in the blood produced in reaction to foreign substances, such as bacteria that cause infections.

A protein produced by the immune system in response to the presence of an antigen (foreign substance). It defends the body against substances identified by the immune system as potentially harmful.

A protein secreted by cells of our immune system in response to infection. The antibody binds to an 'enemy' molecule, in this case a specific part of the hepatitis C virus. this is meant to prevent the virus from infecting other cells or destroy it. As with other viral infections, the presence of antibodies does not necessarily mean a virus will be eliminated from the body.

Antibodies help the body develop immunity to disease. Blood proteins are produced in response to a disease and help the body fight against the particular disease. [Talking Glossary

Molecules produced by B cells in response to specific proteins (antigens) carried by infected cells. Antibodies are directed against specific infections and help fight the disease.

A protein that the body produces after fighting an infection.

Drug used to kill organisms that cause disease. Since some cancer treatments can reduce your body's ability to fight infection, antibiotics may be used to treat or prevent (prophylactic) these infections.

The body’s ”soldier molecules”, produced by the immune system to attack and label invaders for destruction by binding to them. Antibodies are large and complex proteins that need sophisticated methods for their industrial production.

A protein that is produced in response to an antigen (often a virus or bacterium). It is able to combine with and neutralize the antigen.

A component of the immune system produced in response to exposure to antigens. Antibodies help eliminate infectious microorganisms in the body.

A protein that is produced by the immune system to help remove foreign substances and fight infections.

Insulin Proteins

A specific protein formed in the blood of warmblooded animals in response to the injection of an antigen.

A specialized protein our immune system (the body's defense system) makes in order to protect us against disease-causing antigens or allergens. While some antibodies are helpful, others may cause potentially harmful responses, including allergic reactions.

A protein produced by B lymphocytes in response to a foreign substance or an invading organism. It often binds very tightly to the foreign substance or cell, inactivating it or marking it so that it can be destroyed.

protein produced by the immune system (especially B lymphocytes) in response to the penetration of a foreign molecule in the organism. It is tightly bound by the antibody to inactivate it or to label it for elimination by the organism.

A protein that is made by certain white blood cells (lymphocytes), in the body, in response to the invasion of a foreign substance.

A protein produced by the body's immune system in response to a foreign substance (antigen). An antibody reacts specifically with the antigen that induced its formation and inactivates the antigen. Our bodies fight off an infection by producing antibodies.

Produced by the immune system to protect the body from infection, antibodies can also be generated in laboratories for specific purposes: e.g. when antibodies interact with the inhibitory molecule Nogo, they inactivate it and allow the growth of axons.

A protein in the immune system that recognizes and attacks foreign substances in the body.

Protein produced by humans and higher animals in response to the presence of a specific antigen.

(Abs) a protein secreted by B lymphocytes in response to an antigen.

A substance created naturally by the body's immune system which helps to fight off bacteria and foreign substances. close window

protein in the blood that are generated in reaction to foreign proteins. antibodies selectively neutralize the foreign proteins, producing immunity to certain microorganisms or their toxins. Tests to determine if you are HIV positive look for HIV antibodies -- evidence that your body is attempting to fight the virus.

a protein produced by the immune system when a foreign substance enters the body. The presence of antibodies is an indicator of a past or possibly current infection. HCV antibodies are written as anti-HCV. The test for anti-HCV is often the first step in diagnosing chronic HCV infection. A positive anti-HCV test must be followed by other laboratory tests in order to confirm the diagnosis. The antibody test alone is not sufficient to make a diagnosis of chronic HCV infection.

Immunization Serum

An infection-fighting protein molecule in blood or secretory fluids that tags, neutralizes, and helps destroy pathogenic microorganisms (e.g., bacteria, viruses) or toxins. Antibodies, known generally as immunoglobulins, are made and secreted by B-lymphocytes in response to stimulation by antigens. Each specific antibody binds only to the specific antigen that stimulated its production.

Gastritis Proteins

(AN-tih-BOD-ee) A type of protein made by certain white blood cells in response to a foreign substance (antigen). Each antibody can bind to only a specific antigen. The purpose of this binding is to help destroy the antigen. Antibodies can work in several ways, depending on the nature of the antigen. Some antibodies destroy antigens directly. Others make it easier for white blood cells to destroy the antigen.

A germ fighter. The immune system makes these when it sees a germ get inside the body. After they are made, they go into the blood. Then they find the germs and help kill them. For each different germ there is one special ANTIBODY that the immune system makes.

A protein on the surface of B cells that is secreted into the blood or lymph in response to an antigenic stimulus, such as a bacterium or virus, and that neutralized the antigen by binding specifically to it.

a protein (immuno-globulin) molecule, produced by the immune system, that recognizes a particular foreign antigen and binds to it; if the antigen is on the surface of a cell, this binding leads to cell aggregation and subsequent destruction. Antibodies attack viruses, bacteria, and other foreign substances in the body.

Immunity Reactivation

Hematology Proteins

a protein produced by the immune system in response to the introduction of a substance (an antigen) recognized as foreign by the body’s immune system. Antibody interacts with the other components of the immune system and can render the antigen harmless, although for various reasons this may not always occur.

Proteins found in the blood, produced by specialised white blood cells called 'B-cells'. B-cells make antibodies when the body recognises that something foreign (unfamiliar) is present, for example infecting bacteria. The antibodies attach themselves to these invaders, which are then destroyed. Scientists can now make synthetic antibodies (sometimes called 'monoclonal antibodies') in the lab, and use them to diagnose and treat disease.

Antibodies are proteins, which are produced by the defense system of the body to eliminate antigens.

an immunoglobulin that binds specifically to a given antigen.

Part of the immune system that helps the body fight infection and foreign substances.

(AN-ti-bod-dee) A protein produced by certain cells in the body in the presence of a specific antigen. The antibody combines with that antigen to neutralize, inhibit or destroy it.

A specific protein produced by the immune system in response to a specific foreign protein or particle called an antigen.

A protein produced by a B cell in response to a specific foreign substance. The antibody can bond with the antigen enabling an immune response. Antibodies are the “soldiers” which protect us against bacteria and viruses that are free in the body (not inside cells) and parasitic infections.

A protein (immunoglobulin) secreted by plasma cells that recognizes antigenic determinants on an antigen.

a substance which normally helps defend the body against infections due to viruses, bacteria, or other foreign organisms.

Proteins that react with antigens on red blood cells and may destroy transfused red blood cells.

Protein produced by the immune system to neutralize infection.

A protective protein produced in the body that fights or otherwise interacts with a foreign substance in the body.

also known as immunoglobulin – a protein produced in the blood by B lymphocytes in response to and then counteracting antigen.

A protein produced by the body in response to an antigen, and capable of combining specifically with that antigen.

A protein produced by the immune system in response to a foreign substance such as a virus or bacterium.

A protein in the blood that is developed by the body as a defence against any antigen. Antibodies attack antigens in the blood stream in order to destroy them. Antibodies can be passed from mother to baby and can also be introduced by immunization or vaccination.

A protein, carried in the blood, produced by the immune to system which will attack germs, viruses, and other invading agents.

(ANN-teh-bah-dee) Any of numerous protein molecules produced by the immune system's B cells as a primary immune defense

any of various blood proteins produced in response to and then counteracting antigens (a foreign substance, such as a toxin).

Genitourinary Proteins

A molecule made by the immune system which circulates in body fluid. An antibody has a specific amino acid sequence which interacts only with the antigen that induces its synthesis.

An antibody which has the ability to attach itself onto the membrane of certain cells, a property which gives these cells a specific activity against an antigen.

a molecule (or immunoglobulin) produced by B cells in response to an antigen. The binding of antibody to antigen leads to the antigen's elimination/destruction.

A protein that destroys or inactivates a specific antigen. Antibodies are found in the blood serum.

Any immunoglobulin molecule produced in direct response to an antigen and which can combine specifically, non-covalently, and reversibly with the antigen which elicited its formation. ( 16)

An immunologically active protein made by B cells in response to a specific antigen.

An antibody is a protein (also called an immunoglobulin) that is manufactured by lymphocytes (a type of white blood cell) to neutralize an antigen or foreign protein. Bacteria, viruses and other microorganisms commonly contain many antigens, as do pollens, dust mites, molds, foods, and other substances. Although many types of antibodies are protective, inappropriate or excessive formation of antibodies may lead to illness. When the body forms a type of antibody called IgE (immunoglobulin E), allergic rhinitis, asthma or eczema may result when the patient is again exposed to the substance which caused IgE antibody formation (allergen).

Molecule produced by certain immune cells that recognizes and interacts with foreign substances in the body (i.e., antigens), including viruses and bacteria. Antibodies play an important role in the immune response; each antibody is specific for one antigen. The presence of antibodies to a certain antigen (e.g., hepatitis C virus) indicates that the patient has previously been exposed to this antigen.

A type of protein molecule produced by cells of the immune system, in response to the presence of a foreign substance, known as an antigen. Antibodies bind to antigens in a precise physico/chemical manner and thus neutralise their activity. Over a lifetime, the body will produce thousands of different antibodies to the range of antigens it encounters. Antibody molecules consist of two "light" and two "heavy" protein chains, only part of which actually come into contact with the antigen. The area of the antibody known as the variable region is different and specific for each type of antibody.

immune system protein produced by humans and higher animals to recognize and neutralize bacteria, viruses, cancerous cells, and other foreign compounds.

Antibodies are proteins produced by the body’s immune system to fight foreign invaders, such as bacteria, allergens, or even transplanted tissue.

Any of various substances produced in the body (by lymphocytes and other special cells), which help to defend the body against infections due to viruses, bacteria, and other foreign organisms.

A protein produced in the body in response to stimulation by an antigen. Antibodies react specifically to antigens in an attempt to neutralize these foreign substances.

A substance produced by the body to defend the body against infection.

A protein molecule produced by the immune system in response to a foreign body, such as the hepatitis B virus. Antibodies can be produced in response to a vaccine or to a natural infection. They circulate in the blood to protect against future infections.

Proteins of the immunes system that recognise antigens and thereby trigger an immune response still exhibiting antigen binding

A protein produced by the body that counteracts the toxic affects of a foreign substance, organism, or disease within the body.

A soluble protein molecule produced and secreted by B cells in response to an antigen, which is capable of binding to that specific antigen.

an immunoglobulin protein secreted by activated plasma cells, which evolve from B-cells. Antibodies are present throughout the blood and tissues; they are produced in response to stimulation by foreign antigens as part of the body’s defense against disease. Specific antibodies bind to and act upon specific antigens; the antigen/antibody reaction forms the basis of humoral (TH2) immunity.

Antibodies are proteins that help white blood cells fight off viruses and bacteria, by binding to foreign invaders and signaling the immune cells to attack.

a protein produced by the immune system in humans and higher animals, which binds to a specific antigen. When antibodies bind to corresponding antigens they set in motion a process to eliminate the antigens.

Disease fighting protein circulating throughout the body to fight disease causing microorganisms (i.e., viruses, bacteria, parasite, fungi); created by specific white blood cells of the immune system in response to a foreign organism entering the body. Antibodies destroy, render ineffective or identify disease causing organisms for destruction by other immune cells. For more information click here.

A substance that helps fight disease. Colostrum is high in antibodies.

A Y-shaped immunoglobulin protein on the surface of B cells produced by the body and secreted into the blood or lymph in response to a specific antigen. They can then combine with the antigen and neutralize it.

the protein produced by B cells that has special receptors that bind specifically to antigens which allows the immune system to recognise self and non-self. They bind to and neutralise pathogens or prepare them for uptake and destruction by phagocytes.

A protein found in the blood that is produced in response to foreign substances (e.g. bacteria or viruses) invading the body. Antibodies protect the body from disease by binding to these organisms and destroying them.

Antigen Antisense

a protein made by white blood cells that reacts with a specific foreign protein as part of the immune response

A protein made by the body’s immune system usually in response to a foreign body, or antigen. Antibodies fight infection.

Members of a class of proteins known as immunoglobins. Antibodies may tag, destroy and neutralize bacteria, viruses or other harmful toxins. Antibodies attack infected cells, making them vulnerable to attack by other elements of the immune system.

A substance produced by the body in response to the introduction of a foreign substance (antigen).

Homologous Proteins

Antigen Antigen Presenting Cell ( APC)

protein that is produced by the immune system as part of the immune response to a foreign substance known as an antigen. Antibodies have the property that they may specifically bind to the foreign substance that created the immune response

A protein molecule in the blood serum or other body fluids that destroys or neutralizes bacteria, viruses, or other harmful toxins. Antibody production occurs in response to the presence of an antagonistic, usually foreign substance (antigen) in the body. They are members of a class of proteins known as immunoglobulins that are produced and secreted by B-lymphocytes in response to stimulation by an antigen. The antigen/antibody reaction forms the basis of humoral (non-cellular) immunity.

a molecule produced by the body in response to a specific antigen; for example, the presence of the poliovirus in the blood provokes the body to create amino acid molecules (antibodies) to counteract it. Antigen refers to any substance that stimulates the body to make antibodies.

Any of various proteins in the blood that are created by the immune system to neutralize foreign substances in the body. The immune system creates antibodies in response to substances in the body that contain foreign antigens, such as viruses.

A type of protein, also known as immunoglobulin, produced by the body normally to fight infection. Several classes of antibodies are known; IgG, IgE, IgA, IgM, IgD. Antibodies are present in the blood and other bodily secretions. In certain disease states (eg.auto-immune disease) antibodies are made that attack the body by forming immune complexes.

A substance made by B-lymphocytes that reacts with antigens (particularly proteins) on viruses, bacteria and some cancer cells to mark them for removal.

a molecule made by the immune system that recognizes and attacks a specific invading germ. The creation of antibodies can be stimulated when you are infected with a germ or if you are vaccinated against it. Antibodies can also be passed from mother to child during breastfeeding.

Part of the human immune system. Identifies and marks invaders (eg, bacteria) for destruction.

A part of the immune system that attacks "foreign" objects in our bodies

The part of the immune system that helps rid the body of foreign substances, such as viruses or bacteria.

A protein (immunoglobulin) molecule, produced by the immune system, that recognizes a particular substance (antigen) and binds to it.

Protein complex (an immunoglobulin) that interacts with an antigen. It is produced by B-Lymphocytes and recognizes specific area of an antigen.

A protein formed in response to the intrusion of an antigen. Antibodies link up with antigens to nullify the harmful effect of the antigen.

See immunoglobulin

(also called an immunoglobulin) - a complex protein that is manufactured by lymphocytes to neutralize or destroy an antigen or foreign protein. Many types of antibodies are protective, however, inappropriate or excessive formation of antibodies may lead to illness.

An immune system protein in the blood that defends against invading foreign agents, such as bacteria. Invading agents contain certain chemical substances called antigens. Each antibody works against a specific antigen. ( See also antigen).

A protein molecule made by the immune system that is designed to intercept and neutralize a specific invading organism or other foreign substance.

protein found in the blood serum which is formed in response to the presence of an antigen.

A Y-shaped protein on the surface of B cells that is secreted into the blood or lymph fluid in response to the presence of an antigen. Each antibody binds to a specific antigen to induce cell apoptosis, or cell death

neutralizing proteins generated in reaction to foreign proteins in the blood and that produce immunity against certain microorganisms or their toxins.

Serum protein formed in response to immunization; antibodies are generally defined in terms of their specific binding to the immunizing antigen.

a molecule (also called an immunoglobulin) produced by a B cell in response to an antigen. The binding of antibody to antigen leads to the antigen's destruction.

a protein produced by the lymphocytes to fight foreign proteins (antigens)

A special protein made by the body's immune system as a defense against foreign material (bacteria, viruses, etc.) that enters the body. It is uniquely designed to attack and neutralize the specific antigen that triggered the immune response.

A protein (also called an immunoglobulin) that is manufactured by plasma cells (a type of white blood cell) to neutralize an allergen. When the body forms a type of antibody called IgE (immunoglobulin E), an allergic response may result when the person is again exposed to the allergen which caused the IgE antibody formation.

Any of a large number of proteins, also called an immunoglobulin, which is produced in response to a specific antigen; part of the body’s disease-fighting mechanism.

a protective agent produced by the body's immune system in response to a foreign substance

A type of protein produced in the blood or in the body tissues that helps the body fight infection.

Essential in immunity, molecule produced by a mature B cell that recognizes and binds specifically to an antigen also called immunoglobulin

A protein produced by the body to eliminate foreign substances, such as bacteria.

A protein, present in the serum, which could injure the donor's cells by attacking the HLA. (pg. 9)

A protein produced by the body's immune system to fight infection or harmful foreign substances (antigens).

immunoglobulin molecule evoked as a response to an antigen which then interacts with the antigen

A protein produced in response to an antigen; an important component of the immune system.

A protein produced by the immune system in response to viruses, bacteria, and other foreign substances. Antibodies help your body recognize infections and fight them. Vaccines work by helping the body produce antibodies to protect against infections. Antibodies circulate in the blood and their presence can indicate a current or past infection.

an immunoglobulin molecule that has a specific amino acid sequence by virtue of which it interacts only with the antigen that induced its synthesis in cells of the lymphoid series (especially plasma cells), or with antigen closely related to it

a large Y shaped protein molecule made by B-cells of the immune system which very selectively binds to other specific protein molecules called antigens. Specific antibodies combine with and inactivate specific viruses, while other specific antibodies mark invading bacteria and cancer cells for destruction by other cells of the immune system.

A globular protein produced by plasma cells that will bind to specific antigens and promote their destruction or removal from the body.

A protein that your immune system makes in response to a foreign substance. Antibodies can be produced in response to a vaccine or to a natural infection. Antibodies usually protect you against future infections.

Substance in immune system defending the body against bacteria, viruses, and diseases.

A protein based material produced by the body as a defensive response to attack by a bacteria or virus (known medically as antigens). The presence of a specific antibody in the body indicates exposure to the specific virus or bacteria that corresponds to that antibody.

Proteins created by immune system against bacteria and viruses.

A blood protein that is produced in response to and counteracts an antigen.

A kind of protein that plays an important role in the body's immune system (p.168).

A protein substance made by the body's immune system in response to a foreign substance, for example a transplanted organ, blood transfusion, virus, or pregnancy. Because the antibodies attack the transplanted organ, transplant patients must take powerful anti-rejection (immunosuppressive) drugs.

a protein produced by immune system cells and released into the blood. Antibodies defend against foreign agents such as bacteria. These agents contain certain substances called antigens. Each antibody works against a specific antigen. See also antigen.

Any of a large number of proteins that are produced normally by specialized B cells after stimulation by an antigen and act specifically against the antigen in an immune response

Protein produced in body tissues in response to the presence of a specific antigen. See antigen.

A substance produced by the body in response to an antigen that specifically reacts with the antigen to destroy, inhibit, or neutralize it. The body produces antibodies as a defense against foreign substances. Antibodies may be identified and measured to determine whether an individual has been infected by a pathogen.

protein produced by the body's immune system that attacks foreign invaders (antigens) Humans as organisms

A protein produced by certain white blood cells in response to a foreign substance (antigen). Each antibody can bind only to a specific antigen. The purpose of this binding is to help destroy the antigen. Antibodies can work in several ways, depending on the nature of the antigen. Some antibodies disable antigens directly. Others make the antigen more vulnerable to destruction by white blood cells.

Immunoglobulin that is secreted by plasma cell; combines with type of antigen that stimulated its production; directs attack against antigen or cell bearing it.

Antibodies and immunoglobins are proteins in the blood. They are produced by the immune system to fight against bacteria, viruses and disease.

A protein substance which combines with an antigen to form the basis of immunity.

A protein produced by the body to neutralize an invading foreign agent or antigen, such as a virus.

A type of serum protein (globulin) synthesized by white blood cells of the lymphoid type in response to an antigenic (foreign substance) stimulus. Antibodies are complex substances formed to neutralize or destroy these antigens in the blood. Antibody activity normally fights infection but can be damaging in allergies and a group of diseases that are called autoimmune diseases.

A substance formed by the human immune system to help defend it against foreign body, such as virus, bacteria, and cancer cells.

An antibody is a protein produced by the immune system in order to protect the body against a foreign substance (antigen).

A molecule produced by animals in response to antigen which has the particular property of combining specifically with the antigen which induced its formation.

A protein produced by a plasma cell in the lymphatic system or bone marrow. An antibody binds to the specific antigen that has stimulated the immune system. Once bound, the antigen can be destroyed by other cells of the immune system.

A serum protein which is formed in response to an antigenic stimulus and reacts specifically with that antigen.

A protein that is produced when the immune system detects a substance that is believed to be foreign. Antibodies inhibit the activity of these substances.

An antibody (or immunoglobulin) is a protein used by the immune system to identify and neutralize foreign objects such as bacteria and viruses. ( WP) Antibodies are the major component of the humoral immune response. They are secreted by B cells and bind to specific antigens. They contribute to immunity via neutralisation, opsonisation, and complement activation.

An antibody or immunoglobulin is a large Y-shaped protein used by the immune system to identify and neutralize foreign objects like bacteria and viruses. Each antibody recognizes a specific antigen unique to its target. This is because the two tips of the "Y" of the antibody contain a (a structure analogous to a lock) that is specific for one particular epitope (analogous to a key) on an antigen, allowing these two structures to precisely bind together.