Comparison of different DNA preparatory methods for development of a universal direct PCR-RFLP workflow for identification of meat origin in food products

Abstract

The quality and quantity of the extracted DNA are two key aspects for a successful PCR (Polymerase Chain Reaction) amplification. Moreover, reduction in time and cost required for DNA extraction are also two considerable factors, in cases when large number of samples are to be analyzed within a limited time-frame and budget. Accordingly, the aim of this study was to compare and optimize performance of five different DNA extraction methods by boiling meat tissues from cattle, buffalo, sheep, goat, chicken, camel, horse and dog in PBS (Phosphate Buffer Saline), distilled water, alkaline lysis buffers 1, 2 or 3. The results indicated that the boiling of meat and its products in alkaline lysis buffers was a good method to extract crude DNA. The optimized crude DNA extraction protocol was coupled with PCR-RFLP (Restriction Fragment Length Polymorphism) analysis for meat species differentiation. This developed workflow was tested on fifty-three commercial beef and mutton samples, out of which three samples were found to be adulterated. In conclusion, the rapid crude DNA extraction protocol has led to the development of a direct PCR-RFLP workflow that is simple, time-saving and cost-effective for PCR-based identification of different meat species.

Keywords:
DNA extraction; direct PCR-RFLP; meat adulteration; species identification