Development of a Duck Genomic Reference Material by Digital PCR Platforms for the Detection of Meat Adulteration

Visual Detection of Chicken Adulteration Based on a Lateral Flow Strip-PCR Strategy

The aim of this study was to develop an accurate, easy-to-use, and cost-effective method for the detection of chicken adulteration based on polymerase chain reaction (PCR) and lateral flow strip (LFS). We compared six DNA extraction methods, namely the cetyltrimethylammonium bromide (CTAB) method, salt method, urea method, SDS method, guanidine isothiocyanate method, and commercial kit method. The chicken cytb gene was used as a target to design specific primers. The specificity and sensitivity of the PCR-LFS system were tested using a self-assembled lateral flow measurement sensor. The results showed that the DNA concentration obtained by salt methods is up to 533 ± 84 ng µL⁻¹, is a suitable replacement for commercial kits. The PCR-LFS method exhibits high specificity at an annealing temperature of 62 °C and does not cross-react with other animal sources. This strategy is also highly sensitive, being able to detect 0.1% of chicken in artificial adulterated meat. The results of the test strips can be observed with the naked eye within 5 min, and this result is consistent with the electrophoresis result, demonstrating its high accuracy. Moreover, the detection system has already been successfully used to detect chicken in commercial samples. Hence, this PCR-LFS strategy provides a potential tool to verify the authenticity of chicken.

Development of a Ladder-Shape Melting Temperature Isothermal Amplification Assay for Detection of Duck Adulteration in Beef

ABSTRACT

Ladder-shape melting temperature isothermal amplification (LMTIA) is a newly developed technology, and the objective of this study was to establish its effectiveness for detection of duck adulteration in beef. LMTIA primers were designed with the prolactin receptor gene of Anas platyrhynchos as the target. The LMTIA reaction system was optimized, and its performance was compared with that of the loop-mediated isothermal amplification (LAMP) assay in terms of specificity, sensitivity, and limit of detection (LOD). Our results showed that the LMTIA assay was able to specifically detect 10 ng of genomic DNAs (gDNAs) of A. platyrhynchos, without detecting 10 ng of gDNAs of Bos taurus, Sus scrofa, Gallus gallus, Capra hircus, Felis catus, and Canis lupus familiaris. The sensitivity of the LMTIA assay was 1 ng of gDNAs of A. platyrhynchos; it was able to detect duck adulteration in beef with a 0.1% LOD. Although the LAMP assay could not clearly distinguish A. platyrhynchos from G. gallus, it had a sensitivity of 10 ng of gDNAs of A. platyrhynchos and a LOD of 1% duck adulteration in beef. This study may help facilitate the surveillance of commercial adulteration of beef with duck meat.

HIGHLIGHTS

Digital PCR-Based Characterization of a g10evo-epsps Gene-Specific Matrix Reference Material for Its Food and Feed Detection

g10evo-epsps is a novel glyphosate herbicide-resistant gene that has been transferred to various crops such as soybean, corn, cotton, and rice. Here, we developed a gene-specific digital Polymerase Chain Reaction (dPCR) detection method for absolute quantitative analysis of g10evo-epsps, and characterized g10evo-epsps certified reference materials (CRM) using ZUTS-33 soybean powder as the candidate material. Stability tests of matrix CRMs demonstrate that these CRMs can be stored stably for 6 months and transported for 10 days at room temperature and withstand summer high temperatures (below 60 °C). CRM characterization is based on the copy number ratio of g10evo-epsps to lectin. Eight qualified laboratories independently validated the CRM using dPCR method, with a measurement of 0.98 (copy/copy) and an extended uncertainty of 0.08 (copy/copy). The g10evo-epsps matrix CRM described here may be used for qualitative and quantitative testing, method evaluation, laboratory quality control, and other related fields.