EXTRACTION OF DNA FROM FORENSIC-TYPE SEXUAL ASSAULT SPECIMENS USING SIMPLE, RAPID SONICATION PROCEDURES

Sonication procedures for the extraction of DNA from forensic-type sem en specimens have been developed, which, when compared to currently ut ilized sperm DNA extraction techniques, are simple, rapid and result i n comparable DNA yields. Sperm DNA extraction by sonication was perfor med on whole semen, seminal stains, buccal swabs and post-coital speci mens. Ultrasound disruption of sperm cells and their ultimate release of cellular DNA has been conducted in the presence of sperm wash buffe rs followed by organic extraction or Chelex(R) 100 with little or no c ompromise to DNA quality, quantity or amplifiability. Two advantages o f sonication over currently used forensic techniques to extract sperm DNA include 1) sperm DNA extraction that occurs within five minutes of sonication compared with an hour or greater for water bath incubation s in classic enzyme digestion DNA extractions and 2) one less preparat ory step with the Chelex/sonication protocol and three less steps with the sonication/organic protocol compared with other procedures thus e liminating potential sample-to-sample cross-contamination. Sperm DNA e xtracted by optimum sonication procedures was used for forensic HLA DQ alpha typing and restriction fragment length polymorphisms analysis wi thout any adverse effects on typing results.