short tandem repeat

(redirected from Single tandem repeats)


A highly polymorphic segment of DNA composed of repetitive stretches of short sequences of 2–6 base pairs of DNA, which serve as genetic markers to track inheritance in families. Microsatellites include dinucleotides, trinucleotides and tetranucleotides, repeated in tandem arrays throughout a genome. The human genome has 50–100,000 microsatellite loci.

short tandem repeat (STR)

short repetitive DNA sequence. The repeat unit is generally 1–13 NUCLEOTIDES in length and the number of repeats varies in different individuals, usually from 5 to 20. The POLYMERASE CHAIN REACTION (PCR) can be used to determine the number of repeats at a LOCUS, by using PRIMERS that anneal either side of the STR, and analysing the size of the resulting PCR product after amplification. Useful for identification of individuals by DNA FINGERPRINTING.Also called microsatellite DNA