The research on the technology of vacuum coating developing fingerprints and the profiling of DNA on the objects of cloth / 中国法医学杂志

Objectives To conduct a research on the possibility and effect factors of latent fingerprints development in clothing objects after vacuum coating, and extracting fingerprints DNA and to probe in the relation among DNA template quantity and genetic loci numbers tested, and the rfu value after coating. Methods To select two groups that are free sweat hands and sweat hands and have them press their fingerprints on the cloth, after coating, and to analyze the effect of time, to quantify and test the targeted fingerprints DNA, to compare the locus numbers tested between white and black cloth. Results As the time is prolonged, the locus numbers tested decrease. The locus numbers tested on the group of sweat hands using the same method after the same placed time are lager than the free sweat hands. When the value of rfu is 600 above, the ratio of the locus numbers tested is more than 90% and the threshold of templates is 0.013ng. The locus numbers tested of white cloth is larger, comparing with black cloth when using the same method. What is more, there exists an prohibitive influence of pigments of the dyed cloth over the PCR amplification, to put it further, the loci numbers tested will be trimmed. Conclusion The technology of vacuum coating can be well used in the area of detecting fingerprint DNA.

Validation of GlobalFiler?PCR Amplification Kit and the STR Polymorphism / 法医学杂志

Objective To test the technical param eters of GlobalFiler?PC R A m plification K it for its ap-plication to forensic application value and to investigate the genetic polym orphism s. Methods The valida-tion w as conducted in sensitivity, m ixed sam ples, species specificity, adaptability, survivability, consistency, peak height balance and stability. The am plification and detection of the genom ic D N A from 373 unre-lated individuals from B eijing H an nationality w ere extracted by autom ation w orkstation. Results Global-Filer?PC R A m plification K it w as adaptive to som e m ixed, degraded and inhibited sam ples. The pow er of sensitivity and adaptability and peak height balance show ed w ell. The distributions of genotype fre-quencies for 21 STR loci in the population w ere all in accordance w ith H ardy-W einberg equilibrium (P>0.05). The PIC value of the 21 STR loci w as am ong 0.536 to 0.940; the H value w as am ong 0.558 to 0.933; the D P value w as am ong 0.783 to 0.992; the PE value w as am ong 0.243 to 0.874. Conclusion GlobalFiler?PC R A m plification K it is suitable for crim inal cases and D N A database in forensic practice. A nd 21 STR loci in B eijing H an nationality have high polym orphism , w hich have ap-plication value in forensic practice and population genetics.