Duplex recombinase polymerase amplification combined with CRISPR/ Cas12a-Cas12a assay for on-site identification of yak meat adulteration

Yak meat is known for its unique flavor and high nutritional value. Its low output results in high prices, and as a result, food fraud is often committed in the marketplace by using low-value cattle meat with similar morphological characteristics to pass off as high-value yak meat. However, the current detection methods for yak meat authenticity are mostly confined to laboratories and suffer from expensive equipment, high professional requirements, and insufficient specificity, making it difficult to realize rapid on-site assay of yak meat authenticity. In this study, a duplex recombinase polymerase amplification combined with CRISPR/Cas12a-Cas12a assay strategy for rapid visual on-site identification of cattle- and yak-derived components was established. With only a portable box containing some cheap and small equipment, the method can accurately identify the authenticity of yak meat products within 1 h. It has been verified that to this method's detection limit can reach to 1 % (w/w) at least for the cattle meat, regardless of raw or cooked products. After testing the blind samples, 52.8 % of the yak meat products were adulterated, which was consistent with the results of the real-time PCR method, proving that the method has good accuracy and practicability. It can be used to achieve accuracy, rapid and on-site assay of the authenticity of various yak meat products.