Sequence-tagged site

A sequence-tagged site (or STS) is a short (200 to 500 base pairs) DNA sequence that has a single occurrence in a genome and whose location and base sequence are known it is detectable by the polymerase chain reaction (PCR), STSs are useful for localizing and orienting the mapping and sequence data reported from many different laboratories and serve as landmarks on the developing physical map of a genome. Expressed sequence tags (ESTs) are STSs derived from cDNAs.