Rapid and sensitive enzyme-linked immunosorbent assay and immunochromatographic assay for the detection of chlortetracycline residues in edible animal tissues

Abstract

Two rapid and sensitive enzyme-linked immunosorbent assays (ELISA) and an immunochromatographic assay (ICA) for the detection of chlortetracycline (CTC) residues in edible animal tissues were developed based on a monoclonal antibody (MAb) produced by using the chlortetracycline-bovine serum albumin (CTC-BSA) conjugate as the immunogen. A total of 50% inhibiting concentration (IC₅₀) of the modified ELISA was 0.66 ng ml⁻¹ and the recoveries from spiked chicken muscle and liver were 78.8–92.2% and 80.3–90.2%, respectively. The corresponding coefficient variations (CVs) were 3.2–9.5% and 6.5–10.2%. The detection limit was 0.06 ng g⁻¹ in chicken muscle and 0.07 ng g⁻¹ in liver. However, the detection limit of ICA was 0.12 ng ml⁻¹, and the recoveries in negative samples spiked at concentrations of 10, 50 and 100 ng g⁻¹ ranged from 79.0% to 88.6% for muscle samples and from 75.2% to 87.0% for liver samples. The cut-off values for the test lines were 80 ng g⁻¹ and the analysis can be completed within 5–10 min. Comparisons with an HPLC method were performed by testing 200 swine muscle samples and chicken muscle samples from local markets, and an agreement rate of 99.5% was obtained between the three methods.

Keywords:

• HPLC
• immunoassays
• ELISA
• immunoassays
• residues
• veterinary drug residues
• antibiotics
• tetracycline
• animal products
• meat

Acknowledgements

This project was supported by a Key Technology R&D Program in Henan Province (102102310198) and Chongqing Normal University. Tao Le and Shan-Hong Yi contributed equally to this work.