Biomedical subjects

Mei-sen Shi

Publications and source records attributed to Mei-sen Shi.

5 recordsLinked to original sources

PubMed2005

[Constructing standard allelic ladders for four short tandem repeat loci and employing them in a population study on Han Nationality of Chengdu in China].

OBJECTIVE: To solve the problems in the accuracy and standardization of short tandem repeats-polymerase chain reaction (STR-PCR) typing, the authors adopted the molecular clone technology in producing the standard allelic ladders of D1S1676, D2S2735, D11S1977 and D22S444 loci and applied them in a population study on the Hans in Chengdu, China. METHODS: PCR was used to produce several different allelic fragments of these loci. PCR products were eluted from the gel and re-amplified by PCR. The purified allelic fragments were then blunt-end subcloned individually into the pGEMR-T plasmid vectors and the recombinant were transfected into competent E.coli DH5alpha TM cells. The results of sequencing confirmed that the size and the construction of the inserts were correct. The recombinant plasmids DNA with the inserts were then used as template for re-amplification to generate the four loci standard ladders. RESULTS: The authors succeeded in producing large quantity of standard allelic ladder of these four loci, with which the genetic polymorphisms of these loci in Chengdu Han population of China were studied. CONCLUSION: This method is of high value for forensic DNA typing to construct standard ladders. D1S1676, D2S2735 loci are robust for forensic analysis in Chinese Han population, whereas the value of D11S1977 and D22S444 loci is limited.

Alleles↗

PubMed2005

[Distribution of haplotypes for four Y-sTR loci and validation in forensic science by using a double-fluorescent multiplex PCR system].

OBJECTIVE: We focus on developing a multiplex PCR system for Y-STR loci that can be detected by double fluorescent system and assessing their usefulness in forensic mixture samples. METHODS: The primers of four Y-STR loci (DYS-GATA-A10, DYS531, DYS557 and DYS448) amplified by multiplex PCR technique were labeled with fluorescence, then the PCR products of these Y-STRs loci were detecting and typing by ABI PRISM310 Genetic Analyzer. RESULTS: When 120 unrelated individuals from the Han population in Chengdu were detected by the system, Y-GATA-A10, DYS531, DYS557 and DYS448 showed 5, 5, 8, 7 alleles, respectively. A total of 78 different haplotypes was identified and the genetic diversity reached 0.9881. To the three cases of mixture stains failed by using conventional autosomal STR analysis, our multiplex system drew conforming conclusion comparing to the suspect's Y-STRs genotypes. CONCLUSION: Our results show that the multiplex system of four Y-STR will be very powerful for Y-STR database establishing, the paternity testing and mixture stains identifying.

Alleles↗

PubMed2005

[DNA samples preparation from single cell and its application in sensitivity test].

OBJECTIVE: To establish a reliable, exact and practical method to prepare DNA samples for sensitivity-test purposes. METHODS: The micromanipulation method was employed to prepare exact quantity DNA samples used to study the sensitivity of Profiler Plus Kit-ABI PRISM 310 system. RESULTS: We succeed in establishing a micromanipulation method to prepare groups of DNA samples, which contain 1-11 cells in turn, and also succeed in using them to study the sensitivity of Profiler Plus Kit-ABI310 system. CONCLUSION: The method we have established is proved to be a reliable, exact and practical way to prepare DNA samples for sensitivity-test purposes.

DNA↗

PubMed2005

Genetic polymorphisms of four STR loci on chromosome X and their forensic applications in a Chinese Han population.

OBJECTIVE: To add DXS7133, GATA198A10, DXS9896 and DXS6797 to the panel of forensically validated X chromosome markers, and apply the multiplex amplification system to a population study and forensic analysis on the Hans of Chengdu. METHODS: The PCR products were detected by the polyacrylamide gel electrophoresis and silver staining method. Hardy-Weinberg equilibrium of females was tested and every forensically interested value was calculated. RESULTS: Sequencing revealed that their common sequence motifs were tetranucleotide repeats. Population genetic data were obtained by analyzing 120 unrelated females and 100 males from Chengdu Han ethnic group. In this population, DXS7133, GATA198A10, DXS9896 and DXS6797 exhibited 6, 6, 11, 8 distinguishable alleles respectively. Chi-square test demonstrated that genotype frequencies in females did not depart from Hardy-Weinberg equilibrium. Power of discrimination for female samples for the four loci were 0.7962, 0.8021, 0.9675, and 0.9444. The parentage testing in 32 cases revealed a typical X-linked inheritance and no mutations. CONCLUSION: DXS7133, GATA198A10, DXS9896 and DXS6797, which are highly polymorphic in Chengdu Han population, are appropriate for individual identification and paternity testing involving a female child.

Asian People↗

PubMed2004

[Genetic polymorphisms of three STR loci on chromosome X and their forensic application in a Chinese Han population].

OBJECTIVE: To understand the allele structure and genetic polymorphism at three STR loci on chromosome X in Chinese Han population and make an evalution of their forensic application. METHODS: EDTA-blood samples were collected from the unrelated individuals in Chengdu, China. After being extracted with Chelex method, the DNA samples were amplified by PCR technique. The PCR products were analyzed by PAG electrophoresis and the approach of automated fluorescence detection. Hardy-Weinberg equilibrium of females was tested and every forensic interested value was calculated. RESULTS: The polymorphisms of all 3 STR loci were obtained from 100 unrelated females and 120 unrelated males from Chinese Han ethnic group. Chi-square tests on the genotype frequencies in females did not reveal deviations from Hardy-Weinberg equilibrium. CONCLUSION: The obtained data are beneficial to understanding the population genetics of the three STR loci in Chinese Han population. For forensic genetics, the obtained data can be used to calculate the probabilities dealing with the paternity test and the individual identification.

China↗