Sulfaquinoxaline Antibody Preparation And Enzyme-linked Immunoassay Methods To Establish

SQ-OVA and SQ-BSA conjugants were prepared by N-(3-Dimethylaminoproyl)-N′-ethylcarbodiimide hydrochloride (EDC) or glutaraldehyde method respectively. Polyclonal antibodies against SQ were obtained by immunizing rabbits and mice with SQ-BSA. The affinity constant of the anti-SQ polyclonal antibody 1405^# was 1.22×10⁸L/mol. The cross reactivity with other SAs was less than 0.17%. Three hybridoms cell lines secreting monoclonal antibody against SQ were obtained. The cross reactivity with other SAs was less than 1×10^-3%. The affinity constant of the anti-SQ monoclonal antibody SQ₁₂A₁₀ was 1.40×10⁹L/mol. An indirect competitive enzyme-linked immunoassay (ELISA) was developed using polycional antibody 1405^# to measure the residues of s ulfaquinoxaline(SQ) in food. The range of standard curve w as 0.3～100ng/mL。The sensitivity of the assay was 0.2ng/mL. The intra-assay and inter-assay CVs were 7.72%～8.43%, and 9.92%～10.79% respectively. The recovery of SQ in milk, honey, chicken and eggs were 93.1%～106.7%, 69.0%～103.5%, 40.0%～73.6%, 50.0%～84.0% respectively. The correlation coefficient between measured and expected values was 0.997 after serial dilutions of the samples with high concentration of SQ.