抗土霉素单克隆抗体的制备及其在虾中土霉素残留的检测应用

研究目的：抗土霉素单克隆抗体的制备和特性分析，并用于间接竞争酶联免疫吸附测定法（icELISA）分析虾样品中土霉素的残留。创新要点：本研究建立分泌抗土霉素单克隆抗体的杂交瘤细胞株，筛选出对虾中土霉素残留检测具有较高灵敏度的单克隆抗体2．4F。研究方法：重要结论：用细胞杂交技术使土霉素．牛血清白蛋白偶联物免疫的BALC／c雌性小鼠的脾细胞与骨髓瘤细胞融合，建立三株分泌抗土霉素单克隆抗体的杂交瘤细胞株（2—4F、7-3G和11-11A），并制备它们的单克隆抗体。通过ieELISA法分析单克隆抗体对土霉素的半抑制质量浓度（IC-50）和交叉反应率，明确其灵敏度和特异性。实验结果发现单克隆抗体2—4F具有最高的灵敏度，对土霉素的IC50为7．01ng／ml，且该单抗特异性强，仅与罗利环素之间有强烈的交叉反应，而与非相关抗生素不发生交叉反应。当利用单克隆抗体2-4F检测虾样品中的土霉素含量时，其批内和批间回收率分别为82％～118％和96％～113％，变异系数分别为3．9％～13．9％和5．5％～14．9％。因此，单克隆抗体2．4F可用于虾产品中土霉素残留分析试剂盒的开发。

Production of a monoclonal antibody against oxytetracycline and its application for oxytetracycline residue detection in shrimp

A novel monoclonal antibody （MAb） against oxytetracycline （OTC） was generated and characterized. The MAb was used in the development of an enzyme-linked immunosorbant assay （ELISA）-based detection system. An OTC-bovine serum albumin （BSA） conjugate was prepared and used in the immunization of mice. A conventional somatic cell fusion technique was used to generate MAb-secreting hybridomas denoted 2-4F, 7-3G, and 11-11A. An indirect competitive ELISA （icELISA） was applied to measure the sensitivity and specificity of each MAb in terms of its 50% inhibitory concentration （IC50） and percentage of cross-reactivity, respectively. MAb 2-4F exhibited the highest sensitivity, with an ICs0 of 7.01 ng/ml. This MAb showed strong cross-reactivity to rolitetracycline, but no cross- reactivity to other unrelated antibiotics. When MAb 2-4F was used to detect OTC from shrimp samples, the recoveries were in the range of 82%-118% for an intra-assay and 96%-113% for an inter-assay. The coefficients of variation of the assays were 3.9%-13.9% and 5.5%-14.9%, respectively.