Development of an ELISA and Immunochromatographic Assay for Tetracycline, Oxytetracycline, and Chlortetracycline Residues in Milk and Honey Based on the Class-Specific Monoclonal Antibody

A sensitive class-specific monoclonal antibody against tetracyclines (TCs) was generated and used to develop an enzyme-linked immunosorbent assay (ELISA) and an immunochromatographic assay for TC, oxytetracycline (OTC), and chlortetracycline (CTC) detection in milk and honey samples. The dynamic range of detection for TC in ELISA was 0.26–2.00 μg L⁻¹ with an IC₅₀ of 0.72 μg L⁻¹. The IC₅₀ value of OTC and CTC was 3.2 and 6.4 μg L⁻¹, respectively. The recovery of TC, OTC, and CTC in milk samples was 82–102, 91–105, and 90–101 %, respectively, and 88–101, 89–101, and 89–95 % in honey samples, respectively. In the immunochromatographic assay, the cutoff values for TC, OTC, and CTC were 15, 15, and 50 μg L⁻¹ in milk, respectively, and 40, 40, and 40 μg L⁻¹ in honey, respectively. The results revealed that ELISA and the immunochromatographic assay can be applied for the rapid and sensitive detection of TC, OTC, and CTC in milk and honey samples.