An evaluation of the polymerase chain reaction method for forensic applications

This paper describes the use of polymerase chain reaction (PCR) for amplifying small amounts of DNA obtained from samples of interest to the forensic scientist. A region of the HLA DQalpha (DQa) locus was amplified in DNA prepared from the following: hair roots, liquid blood, blood-stains, semen and vaginal swabs (semen free and semen contaminated). A population study was conducted using DNA from 78 unrelated individuals. The observed distribution of HLA DQa alleles varied from that reported for an American population but obeyed the Hardy-Weinberg equilibrium. Interpretation problems associated with the PCR technique are discussed.