Efficacy of different DNA polymerase enzymes in PCR amplification of forensic bovine DNA

Abstract

DNA profiling of exhibits that originate from forensic stock theft cases is routinely used as a tool to link suspects to the crime or scene. DNA derived from aged or degraded samples is often highly fragmented which compromises the efficiency for obtaining a complete genotypic profile using PCR. Conventional polymerases such as Taq, lack certain repair mechanisms for use on degraded DNA templates. New generation polymerases are known to have high fidelity characteristics. The aim of this study was to determine the efficiency of Restorase®, a novel DNA polymerase blend that is known to repair damaged DNA and the FastStart High Fidelity PCR System enzymes, on degraded forensic bovine samples using PCR-based methodology. Bovine meat samples were subjected to different degrees of degradation in the sun and in the shade during summer and winter seasons. DNA was extracted, subjected to PCR amplification using 16 bovine microsatellites and genotypes were generated for analyses. Rapid degradation of samples was observed during winter while during summer samples tend to dry out. Restorase® exhibited high enzyme activity on degraded samples as compared with FastStart and Taq DNA polymerase. Some of the markers that failed to be successfully amplified by Taq polymerase, such as ETH10 and SPS115 were recovered using Restorase®. Markers such as BM1818, BM2113, ETH3, INRA23 and TGLA227 remained active throughout the experiment using all the enzymes, and therefore can form a basis of the bovine marker panel. Restorase® was found to be an alternative enzyme for use in bovine forensic analysis. Copyright