[Show abstract][Hide abstract] ABSTRACT: To explore the feasibility of biological method to identify the biological attribute of samples at crime scene.
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). Three pairs of specific primers were designed for blood stain, saliva stain and semen stain based on the different target genes in three specific tissues and the primers were amplified using real-time fluorescent quantitative PCR. The differences in these biological samples were evaluated by melting temperature (Tm) values and the size of the amplification fragment.
The Tm values of blood stain, saliva stain and semen stain were (84.5 +/- 0.2) degrees C, (76.9 +/- 0.3) degrees C and (88.5 +/- 0.2) degrees C, respectively. The length of PCR fragments of them was 177bp, 134bp and 294bp, respectively.
Compared with the routine method, RT-PCR with real-time fluorescent quantitative PCR is highly specific, sensitive and reliable to identify the biological attribute of evidence, and can be potentially applied to determine evidence attribute in forensic practice.
No preview · Article · Aug 2013 · Fa yi xue za zhi
[Show abstract][Hide abstract] ABSTRACT: To establish a rapid STR genotyping method for individual identification.
Two hundred blood samples from FTA were collected. Equal amount of blood were collected by puncher and analyzed using two methods (6+1 STR kit in combination with EX-Q20 electrophoresis and Sinofiler kit in combination with POP4 electrophoresis). Consuming time and results of two methods were compared.
6+1 STR kit in combination with EX-Q20 electrophoresis method can obtain all genotyping results and be shorter time.
6+1 STR kit in combination with EX-Q20 electrophoresis method is used to STR genotyping with accurate, reliable results and this new method is potential value in mass personnel investigation and comparison in major criminal cases. It also can raise the work efficiency.
No preview · Article · Dec 2011 · Fa yi xue za zhi
[Show abstract][Hide abstract] ABSTRACT: To investigate the expression of 18S rRNA and beta-actin mRNA in bloodstain between 8 and 15 days after death and extrapolate the time of bloodstain formation.
RNA in dried bloodstain at different times was extracted, then quantified for 18S rRNA and beta-actin mRNA by real-time RT-PCR. The bloodstain formation time was deduced based on the changes of the ratio of 18S rRNA to beta-actin mRNA at different time points.
The ratio of 18S rRNA to beta-actin mRNA increased gradually with time, indicating that rRNA and mRNA degraded in different rate with time. CONCLUSION; The ratio of 18S rRNA to beta-actin mRNA could be used for estimating the time of bloodstain formation in some period.
No preview · Article · Oct 2010 · Fa yi xue za zhi
[Show abstract][Hide abstract] ABSTRACT: To investigate the effect of different PCR amplification volume on the accuracy of human identification test.
Human genome DNA samples were amplified using ABI PRISM Profiler Plus kits in 50 microliters, 25 microliters, 12.5 microliters, and 6.25 microliters reaction volume, respectively. The thermocycle parameters were the same. All PCR products were then electrophoresized on ABI PRISM 310 Genetic Analyzer, 377 DNA Sequencer, and 3100 Genetic Analyzer. Data were processed by ABI PRISM GeneScan and Genotyper software.
The less reaction volume, the more alleles losing or alleles adding observed.
Non-standard volume of PCR amplification reaction should be used carefully in human identification test, especially when the sample DNA quality is not so satisfied.
No preview · Article · Sep 2002 · Fa yi xue za zhi