Abstract
Blood samples were obtained from 120 healthy unrelated males from the Han ethnic group in Chengdu of China. The DNA was extracted by using Chelex 100 protocol as described by Walsh et al. (1). The allelic variation at the three Y-STR loci, named as DYS447, DYS449 and DYS450, were analyzed by PCR amplification system. Each PCR reaction was performed in a 37.5 µL containing 2-10 ng DNA, 1 X Taq buffer, 1.5 mM MgCl2, 200 RM each dNTP (Pharmacia Biotech, Sweden), 1.5 U Taq polymerase (NEB, UK), 0.3 RM each primer in a Perkin-Elmer 9600 thermocycler (ABI, Foster City, CA). The PCR products were analyzed by horizontal non-denaturing polyacrylamide gel electrophoresis with discontinuous buffer system and visualized by silver staining (2). Alleles were designated according to recommendation of the International Society of Forensic Genetics (3). The gene diversities, the haplotypes diversity and the standard errors of diversity were calculated in accordance with Hou's method (4).
