Genotyping DNA isolated from UV irradiated human bloodstains using whole genome amplification.

Abstract

Analysis of DNA polymorphisms are the primary technique used for personal identification in forensic cases. However, DNA samples collected as evidence from crime scenes are usually degraded by environmental, physical, and chemical factors, which may interfere with the PCR analysis and, consequently, personal identification. Whole genome amplification (WGA) is a useful method to amplify genomic DNA from samples containing low quantity and poor quality of DNA, and it approach that shows promise to overcome the limited small fragments based upon random fragmentation by universal priming sites. In this study, we describe the use of WGA to genotype 15 short tandem repeat (STR) loci from dried blood samples irradiated with different types of ultraviolet (UV) light (UVA, UVB, and UVC). The result showed that UVC was the most damaging to DNA, followed by UVB and UVA. Samples exposed to UVA could be genotyped for all STR loci with or without WGA. For UVB and UVC irradiated blood samples, a greater number of STR loci could be genotyped after WGA. Although it hard to amplified a few higher molecular weight alleles, overall, the WGA method was useful in genotyping template DNA of poor quality but low quantity.