Genetic data of four X-chromosomal STRs in a population sample of Santa Catarina, Brazil

Population: A total of 184 healthy unrelated individuals (70 females and 114 males), autochthonous from Santa Catarina, Brazil.     

短串联重复分型异常

短串联重复序列(STR)已被广泛应用于法医学的个体识别和亲子鉴定中。大多数情况下,STR的分型均得到了准确、可靠的结果,但是在应用中也发现了一些异常的分型现象。引起这些异常现象原因很多,有DNA的遗传性变异、DNA模板质量不好、分型试剂或方法的不同、PCR反应中非特异性反应以及异常的电泳行为等。这些异常的结果会干扰STR分型结果的解析。     

Population data for a novel, highly discriminating tetra-local Y-chromosome short tandem repeat: DYS503

Population: Population samples for gene diversity studies were obtained from the Virginia Division of Forensic Science (bloodstains), Richmond, VA. Ninety-eight Caucasian and 100 African American samples were included in this study.     

DNA sequence characterization of the FGA STR locus in the free state population of South Africa

POPULATION: African (n=52), Mixed Ancestry (n=5), Caucasian (n=4) SAN (n=1).     

Polymorphism of eight X-chromosomal STRs in a Japanese population

Eight X-chromosomal short tandem repeat (X-STR) markers were analyzed in 258 unrelated Japanese (144 males and 114 females) using Mentype^® Argus X-8 PCR Amplification Kit (Biotype AG) which contains DXS7132, DXS7423, DXS8378, DXS10074, DXS10101, DXS10134, DXS10135 and HPRTB. The DXS10135 locus proved to be highly polymorphic marker (PIC: 0.945) and the DXS7423 showed the lowest value (PIC: 0.453). The exact test for genotype distribution showed no significant deviation from the Hardy-Weinberg equilibrium.     

Laser microdissection separation of pure spermatozoa from epithelial cells for short tandem repeat analysis

Short tandem repeat (STR) analysis is a valuable tool in identifying the source of biological stains, particularly from the investigation of sexual assault crimes. Difficulties in analysis arise primarily in the interpretation of mixed genotypes when cell separation of the sexual assailant's sperm from the victim's cells is incomplete. The forensic community continues to seek improvements in cell separation methods from mixtures for DNA typing. The feasibility of applying laser microdissection (LMD) technology to precisely separate sexual assault cell mixtures by visual inspection coupled with laser dissection was assessed through three experiments. First, various histological stains were evaluated for use with LMD and DNA analysis. Second, different DNA isolation methods were evaluated on LMD-collected cells. Finally, STR analysis was performed on LMD-separated sperm cells from mixtures of semen and female buccal epithelial cells. The results indicated (a) hematoxylin/eosin staining performed best in its ability to differentiate sperm and epithelial cells while exhibiting the least negative effect on further downstream analysis; (b) both QIAamp and Lyse-N-Go methods were useful for recovery of DNA from LMD-collected sperm cells; and (c) LMD separation provided clear STR profiles of the male donor with the absence of any additional alleles from the female donor. This report describes an efficient, low-manipulation LMD method for the efficient separation of spermatozoa from two-donor sperm/epithelial cell mixtures.