DNA test of aged skull is always a difficult problem in the field of forensic science,as the skull contains little DNA,and the DNA degrades badly.Here,an improved method is introduced for DNA test of aged skulls.Taking the skulls in recent cases for example,the optimization was carried out from the selection of materials,concentration and recovery of demineralized solution,high volume extraction and purification of DNA,etc.Finally,the results of autosomal and Y chromosome STR polymorphism were obtained successfully.The results showed that petrosal part of temporal bone could be the preferred extraction site for the test of aged skulls,with a higher success rate compared with other parts of the skull;in addition,the use of Amicon Ultra-15 10K centrifugal ultrafiltration tubes could remove a large number of small molecules,such as water and ions in the decalcification solution,so as to retain and recycle the large molecules of DNA,which effectively reduced the amount of DNA loss;furthermore,the quality of DNA was poor in aged skulls,so increasing the amount of bone powder used and increasing the extraction and purification system could also significantly improve the amount of DNA recovered.This method improves the quantity and quality of DNA recovered from aged skull,and can provide reference for the follow-up DNA test of similar aged bones and teeth.
forensic geneticsaged skullpetrosal part of temporal boneDNA extractionrecovery of demineralized solution