Locus (plural: Loci) | DNA Testing Glossary
A locus (plural: loci) is a specific, fixed position on a chromosome where a particular gene or genetic marker is located. In DNA relationship testing, the laboratory examines the same set of STR loci in each person being tested. Each person has two alleles at every locus — one from each biological parent. The lab compares alleles at each locus between a child and an alleged parent to see whether the expected inheritance pattern is present. Testing more loci improves the statistical strength of the result and reduces the chance of a coincidental match between unrelated individuals.
Related Terms
Allele, Genetic Marker, STR (Short Tandem Repeat), Combined Paternity Index, DNA Profile
