CONFIRMATION OF PM TYPING PROTOCOLS FOR CONSISTENT AND RELIABLE RESULTS

A recent report in the Perkin Elmer ''Forensic Forum'' bulletin descri bed a modification to the previously published PM typing protocol indi cating that in order to obtain consistent and reliable PM and DQA1 typ ing results, disodium EDTA should be added to the post-amplification m ixture before denaturation of the DNA fragments. The analysis and vali dation of this suggestion is described in the accompanying paper. We r eport the evaluation of this additional step when typing for PM allele s and conclude that the standard operating procedures currently enforc ed at the Palm Beach County Sheriff's Office and Indian River crime la boratories do not necessitate the need for the addition of disodium ED TA to the PM amplified products prior to the heat denaturation step. F urther, depending on an individual laboratory's PM protocol, the recom mendation by Perkin Elmer to add disodium EDTA to PM amplified product s before typing has merit and should be carefully considered when dete rmining laboratory PM typing protocols.