STR Typing And Application In Forensic Medicine Of Human Fingerprint

Objective Establish the DNA examination methods to the bloody latent fingerprints and sweaty latent fingerprints deposited on porous and nonporous carriers.Methods The biological sample DNA were successfully extracted with chelex-100- Microcon-100, magetic bead, silicic bead and filter method. Then the amplification multiplex was conducted in PCR System2400, 9700 thermal cycler, finally, we used 3100 Genetic Analyzer for analysis of amplification products. Results In order to evaluate the performance of latent fingerprint analysis in a criminal case,experinments with varying condition were carried out to improve our understanding of low copy number(LCN)DNA typing.The result showed,the sweaty fingerprints developped with copper powder,aluminium powder,fluorescence powder,black magnetic powder,ninhydrin,fluoresent liquid and cyanoatrylate ("502" glue) can be successfully STR typed,except the ones developped with AgNO3.In addition,benzidine,ninhydrin,gold powder and silver powder have not obvious influence on DNA examination of fresh or aged bloody latent fingerprints.The development of Amino Black is likely to influence further DNA examination if ethanol washing is improper. Conclusion We set up the DNA examination protocols of latent fingerprint on all kinds of carriers.In a few criminal cases,the method were successfully applied.