For a paternity test, only certain areas of the repetitive DNA in the non-coding regions are important.  Scientists call these repeats short tandem repeats (STRs). STRs consist of two to seven DNA bases that can be repeated several times. For example, the sequence “GATC” can occur eight times in one person but fifteen times in another. They are as individual as a fingerprint and make it possible to identify people almost uniquely (with the exception of identical twins).