Effect of DNA extraction methods on the detection of porcine ingredients in halal cosmetics using real-time PCR

In recent years, halal cosmetics have attracted considerable attention worldwide. We developed a real-time PCR assay based on the mitochondrial gene ndh5 for rapid detection of porcine ingredients in halal cosmetic products. We also compared several DNA extraction methods for the most efficient approach in different types of cosmetics. Porcine template DNA was spiked into three types of cosmetics (liquid-type and powder-type mask packs, and cream) and extracted with five commercial DNA extraction kits and the CTAB method. The extraction efficiency of each method was evaluated by determining the detection limits of real-time PCR assay. The lowest detection limit of real-time PCR for each cosmetic product was as follows: 2.28 × 10⁰ copies for liquid-type mask pack when the Power Prep™ DNA extraction kit and TIANamp Genomic DNA kit were used, 2.28 × 10¹ copies for powder-type mask pack when QIAamp DNA stool mini kit and the Power Prep™ DNA extraction kit were used, and 2.28 × 10⁰ copies for cream when the Power Prep™ DNA extraction kit was used. The pig-specific real-time PCR assay facilitated the detection of trace amounts of the template DNA in cosmetics, and an appropriate DNA extraction method was used depending on the type of cosmetics.