Identification of vaginal fluid, saliva, and feces using microbial signatures in a Han Chinese population.

In recent years, forensic scientists have focused on the discrimination of body fluids using microbial signatures. In this study, we performed PCR-based detection of microbial signatures of vaginal fluid, saliva, and feces in a Han Chinese population. We investigated the 16S rRNA genes of Lactobacillus crispatus, Lactobacillus gasseri, Lactobacillus jensenii, Lactobacillus iners, and Atopobium vaginae in vaginal fluid, the 16S rRNA and the glucosyltransferase enzyme genes of Streptococcus salivarius and Streptococcus mutans in saliva, and the 16S rRNA genes of Enterococcus species, the RNA polymerase β-subunit gene of Bacteroides uniformis and Bacteroides vulgatus, and the α-1-6 mannanase gene of Bacteroides thetaiotaomicron in feces.

[Application of Ion Torrent PGM™ System in Detection of Fetal DNA in Maternal Plasma].

Objective: To explore the feasibility of detecting of Y-STR of fetal DNA in maternal plasma using Ion Torrent PGM™ System.

Methods: A total of 16 fetal DNA samples from maternal plasmas (8 cases from 38 weeks gestational age and 8 ones from 12 weeks) were prepared and a multiplex assay with 7 STR loci (DYS390, DYS391, DYS393, DYS438, DYS437, DYS456, DYS635) was designed for multiplex-PCR amplification. Using Ion Torrent PGM™ System, the results of Y-STR sequences and capillary electrophoresis were obtained and compared.

[Determination of the biological attribute of evidence at the scene using reverse transcription PCR and real-time fluorescent quantitative PCR].

Objective: To explore the feasibility of biological method to identify the biological attribute of samples at crime scene.

Methods: Thirty samples of ten blood stains, ten saliva stains and ten semen stains were selected, and all the samples were processed by the routine method and biomolecular method, respectively. Both RNA and DNA were isolated using DNA-RNA co-extraction technology and the mRNA was converted into cDNA using reverse transcription PCR (RT-PCR).

[Forensic application of expressmarker 22 STR loci direct PCR amplification kit].

Objective: To explore the application value of Expressmarker 22 STR loci direct PCR amplification kit.

Methods: One thousand nine hundred and forty-eight samples (including samples spotted on FTA cards, filter papers and case samples) were tested using Expressmarker 22 STR loci direct PCR amplification kit. At the same time, all were tested using Sinofiler kit, Identifiler kit and PowerPlex 16 kit respectively for comparison.