qPCR Analysis of DNA Extracted from Adulterated Personal Care Products Using a Modified CTAB-based DNA Extraction Method

Personal care and cosmetic products are susceptible to adulteration due to the high market demand. Manufacturers tend to substitute plant-based materials with animal-derived alternatives as a cost-saving measure. The unlabelled adulterated ingredients arouse concern among consumers, especially the vegan community, as this fraudulent action can lead to adverse effects such as intoxication and allergy. To overcome this issue, Real-Time Polymerase Chain Reaction (qPCR) is an ideal technique for species identification based on specific primer design to detect targeted DNA from adulterated personal care products. In this work, cetyltrimethylammonium bromide (CTAB) used for DNA extraction method was modified to ensure successful detection and authentication of target species in personal care products. Robustness of the modified CTAB method was evaluated by comparing the DNA purity and yield across various samples. The developed CTAB method showed a promising result of DNA A260/280 purity ratio ranging 1.15-2.12, whereas the commercial kits ranged 1.39-3.34 and 1.55-1.79 for the PowerPrepTM Gelatin DNA Extraction Kit and the PrimeWay Plant DNA Extraction Kit respectively. The extracted DNA were further analysed using qPCR, revealing detectable DNA in all tested products except for the shampoo sample used in this study, with concentration of porcine DNA ranging 2.94 x 10-4 - 1.46 x 10-2. This modified CTAB method can be served as effective in-house method for species authentication in common personal care products.