Extraction of single-copy nuclear DNA from forensic specimens with a variety of postmortem histories

Specimens of human bone. tceth and dried hlood spots frol11 3 months to 91 years old, with a variety of postmortem histories. were used in a comparative study of recovery of inglecopy nuclear DNA sequences from forensic material. Sequences of the amelogenin and HLA·DPB I genes were chosen for their value in sexing and identification. Sequences of the mitochondrial non·coding region V were also amplified to compare the recovery of mitochondrial and single·copy nuclear DNA. A variation of the silica method for DNA extraction was refined for application to the forensic specimens in this sample. Single·copy nuclear DNA was amplified from 100% of recent postoperative bone specimens (n =6), 80% of forensic teeth and bone pecimens (n = 10), 78% of recently extracted teeth (n = 18), 78% of exhumed bone up to 91 years old (n = 37) and 69% of 15 year old bone specimens fixed in 10% fomlalin (n = 20). Amelogenin sexing was correc in 85% of cases (n = 74) in which the sex of the donor had been recorded. There was no correlation between the age of the specimen and the extent of DNA preservation.