Preparation and validation of the polyclonal antibodies for detection of chlortetracycline residues

Abstract

To detect chlortetracycline (CTC) residues in edible animal tissues, CTC-specific polyclonal antibodies were prepared and applied to enzyme-linked immunosorbent assays (ELISA). By reacting CTC with sodium chloroacetate in 0.1 mol l−1 phosphate buffer (pH 8.0), a hapten of carboxymethyl chlortetracycline (CMCTC) was synthesised and linked to bovine serum albumin (BSA) to prepare artificial antigen (CMCTC–BSA). Polyclonal antibodies were raised in New Zealand rabbits by immunisation of CMCTC–BSA. The ELISA method allowed CTC detection in a range of 0.1–312.5 µg kg−1 with 15.0±6.0 µg kg−1 of 50% inhibition concentration. After validation by high-performance liquid chromatography method and comparison with commercial kit, the method was proved to be rapid, sensitive, economic and reliable for screening CTC residues in edible animal tissues without interference with other compounds.