Comparison of four isothermal amplification techniques: LAMP, SEA, CPA, and RPA for the identification of chicken adulteration

In recent years, with growing concern worldwide about meat and meat product adulteration, dozens of DNA-based isothermal amplification techniques have been developed and applied to detect meat adulteration. Thus, we evaluated four mainstream isothermal amplification techniques, including loop-mediated isothermal amplification (LAMP), denaturation bubble-mediated strand exchange amplification (SEA), cross-priming amplification (CPA), and recombinase polymerase amplification (RPA) focusing on the limit of detection, simplicity, amplification time and cost to confirm the most effective and suitable method for point-of-care testing (POCT) of chicken and chicken product authenticity. The LAMP, CPA, and RPA primers all targeted the chicken mitochondrial cytochrome b gene. The SEA primers were provided by the SEA kit. All methods showed good specificity to chicken. Among them, LAMP, CPA, and RPA have the lowest detection limit, with 1.2 pg μL−1. As low as 0.1% chicken in mutton can be detected in LAMP and RPA methods. Although RPA costs 10 times more than LAMP, the system and primers of LAMP are too complex. Therefore, it must be admitted that RPA is the most suitable method in multiplex detection, and LAMP is much better than the other three methods in single-plex detection. Our research provides an excellent reference value for the rapid on-site detection of meat and meat product adulteration.