Abstract:

In order to obtain the specific monoclonal antibody against cadmium chelate, 1-（4-isothiocyanobenzyl） ethylenediamine-N, N, N′, N′-tetraacetic acid （ITCBE） was used as the bifunctional chelator to prepare the hapten. The product was then coupled with keyhole limpet hemocyanin Cd-ITCBE-KLH or bovine serum albumin （BSA） to produce immunogen and coating antigen. After an identification of the antigen and the immunization of Balb/c mice, the hybridomas were screened via the fusion of spleen cells and SP2/0 myeloma cells, and positive clones against Cd-ITCBE-BSA were selected by subcloning. Finally, mAb 3A9D9G7 was obtained from the ascites. ELISA results indicate that mAb 3A9D9G7 with a κ-type light chain, whose ascites titer and apparent affinity constant are respectively 4 × 10 ^-4 and 1.44 × 10¹⁰ mol/L, belongs to IgM subclass. It is of a sensitivity of lower than 50μg/L and a cross-reactivity rate of less than 0. 90%. Thus, mAb 3A9D9G7 is highly specific against cadmium chelate and is suitable for the rapid detection of cadmium residue in environment and food samoles.

Key words: cadmium, bifunctional chelator, monoclonal antibody, preparation, identification