Repeated DNA sequences in which the repeat units are typically three, four, or five base pairs. Alternately, a method of analysing DNA based on variations in the number of these repeat units.

A short DNA motif (pattern) repeated in tandem. ATGC repeated eleven times would give the marker a value or allele of 11.

A short (2 to 5 bases) DNA sequence that repeats itself in tandem. STRs are used in DNA profiling.

Each location, or marker, tested on the Y chromosome consists of a set of base elements repeated several times in the same sequence. The number of repeats provide a comparison between individual in genealogy.

A short tandem repeat (STR) in DNA is a class of polymorphisms that occurs when a pattern of two or more nucleotides are repeated and the repeated sequences are directly adjacent to each other. The pattern can range in length from 2 to 10 base pairs (bp) (for example (CATG)n in a genomic region) and is typically in the non-coding intron region, making it junk DNA. By examining several STR loci and counting how many repeats of a specific STR sequence there are at a given locus, it is possible to create a unique genetic profile of an individual.