Definition for Microsatellite
From Biology Forums Dictionary
1) Sequence of randomly repetitive DNA, 10 to 100 base pairs long.
2) A microsatellite is a simple sequence repeat (SSR). It might be a homopolymer ('...TTTTTTT...'), a dinucleotide repeat ('....CACACACACACACA.....'), trinucleotide repeat ('....AGTAGTAGTAGTAGT...') etc. Due to polymerase slip (a.k.a. polymerase chatter), during DNA replication there is a slight chance these repeat sequences may become altered; copies of the repeat unit can be created or removed. Consequently, the exact number of repeat units may differ between unrelated individuals. Considering all the known microsatellite markers, no two individuals are identical. This is the basis for forensic DNA identification and for testing of familial relationships (e.g. paternity testing).