Monoclonal antibody-based sandwich enzyme-linked immunosorbent assay for porcine hemoglobin quantification

The major objective of this study was to establish a monoclonal antibody (mAb)-based sandwich enzyme-linked immunosorbent assay (ELISA) for the quantification of porcine hemoglobin (P_Hb) in raw meat products. Before assay development, two mAbs immunoreactive to P_Hb β subunit with different epitopes were characterized. The optimized immunoassay was specific to P_Hb and had a wide P_Hb working range from 15.6 µg/mL to 3,000 µg/mL and high reproducibility with low coefficient of variations (CV < 20%). Through this assay, the estimated P_Hb residuals in pork loin and shoulder meats were 0.4 mg/g and 1.1 mg/g, respectively. In addition, this immunoassay could effectively quantify P_Hb in laboratory-spiked meats (pork loin, pork shoulder, and turkey breast) with acceptable recovery. Overall, this is the first mAb-based sandwich ELISA that is suitable for the government, food industry, and third-party authority to monitor P_Hb residuals or porcine blood adulteration in raw pork and pork-free meat products.