Preparation of an anti-diethylstilbestrol monoclonal antibody and development of an indirect competitive ELISA to detect diethylstilbestrol in biological samples

Based on the preparation of an anti-diethylstilbestrol (DES) monoclonal antibody, a simple and convenient indirect competitive enzyme-linked immunosorbent assay (ELISA) method for DES detection has been developed. The monoclonal antibody demonstrated high sensitivity to DES with an IC50 value of 275 pg mL−1 and detection limit (LOD) of 90 pg mL−1. The specificity of the assay was studied by measuring cross-reactivity of the antibody with structurally related compounds of ethinyl estradiol (<7%), estrone (<0.1%), estriol (<0.1%), and diethylstilbestrol benzoate (<0.1%). Chicken, fish, shrimp, urine and bile spiked with different concentration of DES were detected by the developed method, and the recovery rates were greater than 79.5%. Intra- and inter-assay variations were about 6%. This method exhibited high stability with a coefficient of variation less than 10% in buffer and in real samples. The LODs in fish/shrimp, liver, feed and urine spiked with DES were 600, 600, 4800 and 600 pg mL−1, respectively. These results confirmed that the antibody to DES was successfully produced and could be used to establish ELISA methods for DES detection in food producing animals.