基于酶标噬菌体抗体的磁分离免疫分析方法

Magnetic Affinity Immunoassay Based Enzyme-Labeled Phage Displayed Antibody

以磁微粒偶联多抗为磁性捕获探针,酶标噬菌体抗体为特异信号检测探针,采用＂磁性捕获探针-待测物-酶标噬菌体抗体探针＂的检测模式,成功建立了一种基于酶标噬菌体抗体的磁分离免疫分析方法。本方法检测β-银环蛇毒素线性范围为0.016-62.5μg/L,回归方程为Y=0.641X＋1.355（R=0.9925,n=13,p〈0.0001）,检出限为0.016μg/L。本方法比传统ELISA法检测灵敏度提高了10倍,与采用酶标单抗复合物探针的双抗体夹心磁分离免疫分析法相比,检测灵敏度提高4倍。本方法灵敏度高,具有较好重现性与特异性,在毒素的痕量检测方面具有广阔的应用前景。

A new magnetic affinity immunoassay（MAIA） strategy based on enzyme-labeled phage displayed antibody was developed. The assay consisted of a sandwich format in which immobilized polyclonal antibody（pcAb） on magnetic microparticle was used for capture probe,and enzyme-labeled phage displayed antibody for specific detection probe to increase enzyme amount and enhance detection signal. By the proposed method, β-bungarotoxin（β-BGT） was successfully detected. A linear relationship between absorbance value and the concentration of β-BGT in the range of 0. 016- 62. 5 μg / L was obtained. The linear regression equation was Y = 0. 641X ＋ 1. 355（ R = 0. 9925,n = 13,p〈0. 0001） with a detection limit of 0. 016 μg / L. In comparison with the traditional ELISA,this method gave a 10-fold better sensitivity in β-BGT detection. This strategy also gave a 4-fold better sensitivity comparing with the MAIA based on enzyme labeled monoclonal antibody（mcAb）. Due to low detection limit,acceptable reproducibility and high specificity,this method holds great promise in toxin trace detection.