(FA), assay is a general term for procedures which utilize the visual detection of fluorescent dyes coupled (conjugated) to antibodies which react with the antigen when present using fluorescent microscopy. FA allows a competent technologist to identify visually the site of the antigen-antibody reaction thereby rendering significant specificity. Variations are further explained below (DFA, IFA, ACIF, ABIF, and Microif).
Immunoglobulin molecule which has been coupled with a fluorescent dye so that it exhibits the property of fluorescence.
Antibody reaction make visible by incorporating a fluorescent dye into the antigen-antibody reaction and examining the specimen with a microscope equipped for fluorescent microscopy.
An antibody coupled with a fluorescent dye, used with a fluorescence microscope to detect antigen on cells, tissues, or microorganisms.
"A method used in microbiology to detect microorganisms usually bacteria. An antibody with an attached fluorescent molecule is applied to a slide containing the bacteria and washed to remove unbound antibody. Under UV light the bacteria to which antibodies are bound will fluoresce revealing their presence." [USAMRIID, p. A-8
