A new useful STR locus for forensic analysis

In order to get more available STR loci for forensic DNA analysis in Chinese populations, we investigated 10 tetranucleotide STR loci on chromosome 9 selected from GDB (D9S917, D9S254, D9S1121, D9S1118, D9S301, D9S1122, D9S922, D9S252, D9S2026, D9S934). Some of these were then chosen for further evaluation. 1039 EDTA-blood samples of unrelated individuals and some biological materials obtained from crime scene were used in this study. Amp-FLP techniques were employed for DNA typing. All alleles were cloned in plasmids and sequenced with an ABI 310. For each locus, the cloned alleles were amplified and the PCR products were mixed to make an allelic ladder for DNA typing. The software POPGENE was used to analyze the allele frequencies and heterozygosities of 10 STR loci in Chinese Han population. The results showed that compared with the other nine loci, allele frequencies of D9S1118 had a preferable distribution in Chinese Han population. The exclusion probability was 0.6405, while the discrimination power was 0.9424. Analyzing biological materials from crime scenes showed that typing D9S1118 had a higher success rate. All of these results suggest that D9S1118 as a marker could be used for forensic DNA analysis in Chinese populations. D 2003 Elsevier Science B.V. All rights reserved.