PURIFICATION OF FORENSIC SPECIMENS FOR THE POLYMERASE CHAIN-REACTION (PCR) ANALYSIS

Purification methods of deoxyribonucleic acid (DNA) from degraded and contaminated forensic samples were investigated for polymerase chain r eaction (PCR) analysis. DNA extracted from putrefied tissue or bloodst ains sometimes contained the copurified contaminant, that was identifi ed as the porphyrin compound (hematin). When contaminated but less deg raded DNA was analyzed by PCR, it was necessary to eliminate the impur ity by anion exchange column chromatography or chelating resin prepara tion, and ultrafiltration using Centricon microconcentrators. When hig hly degraded DNA was analyzed, trace amounts of high molecular weight DNA was recovered by electroelution method, and then further purified by both column chromatography and ultrafiltration. From thus purified samples, the amelogenin gene for sex determination could be amplified by dual PCR technique.