TaqMan qPCR quantification of the Cytb gene for precise determination of camel milk in dairy products

Abstract

Camel milk often faces quality control problems because it is vulnerable to adulteration with inferior dairy sources or plant-derived additives. Many existing DNA-based detection methods rely on suitable endogenous reference genes. This study aimed to develop an absolute quantification strategy based on real-time quantitative polymerase chain reaction using TaqMan probes. A recombinant plasmid standard containing camel-specific cytochrome b ( Cytb ) genes was designed. The resulting standard curve revealed high linearity ( R ² = 0.9982) across six orders of magnitude, enabling precise quantification of copy numbers. The primers and probes demonstrated high specificity for camel DNA, and the plasmid standards met quality criteria (A260/280 = 1.82; concentration deviation <2%). The method achieved a sensitivity of 6.39 × 10² copies/μL. For samples containing 5%–100% of camel milk, the coefficient of variation ranged from 0.99% to 5.20%, and the recovery rates for spiked products ranged from 97.5% to 107.5%. By providing absolute quantification without requiring a reference gene, this method offers a robust solution for detecting camel milk adulteration in dairy products.