SNP genotyping of forensic casework samples using the 52 SNPforID markers

The analysis of degraded DNA is one of the biggest challenges in forensic casework. SNPs, which can be amplified using small amplicons, have previously been successfully applied to the profiling of forensic evidence that could not be analyzed using conventional STRs. Here we selected the 52 SNPforID SNP markers, with amplicons that ranged in size from 59 bp to 115 bp, and used them to profile a range of casework samples from Malaysia. DNA degradation is a common problem in Malaysia due to the high temperatures and humidity. To carry out the study we modified the 52 SNPforID markers into four 13-plex SNaPshot assays to enable easier interpretation of profiles on the ABI PRISM (R) 310 and 3500. Fifty-one crime samples comprising bloodstains on cloth, swabs, and a mat and 2 swabs of trace DNA from 10 crime scenes in Malaysia were profiled after DNA extraction using a phenol- chloroform method. The samples were also subjected to STR analysis using the Powerplex (R) 16 system (Promega), which resulted in only 17 full profiles and 9 partial profiles; using SNPs, 36 full profiles and 5 partial profiles could be generated. (C) 2013 Elsevier Ireland Ltd. All rights reserved.