Ahn Ki Chang, Lohstroh Pete, Gee Shirley J, Gee Nancy A, Lasley Bill, Hammock Bruce D
Department of Entomology and UCD Cancer Research Center, University of California, Davis, California 95616, USA.
Anal Chem. 2007 Dec 1;79(23):8883-90. doi: 10.1021/ac070675l. Epub 2007 Nov 6.
We have developed a sensitive, automated, competitive chemiluminescent immunoassay for the detection of 3-phenoxybenzoic acid (3-PBA), a metabolite common to many pyrethroid insecticides. The system uses a competitive hapten-protein conjugate that has been labeled with an acridinium ester as the chemiluminescent probe and secondary antibody-coated paramagnetic particles for the separation. After the immunoassay reagents and samples are combined for the competitive incubation step, a fully automated system is used to load the postincubation mixture into a delivery cuvette, facilitating the subsequent magnetic separation of the immunocomplex and the measurement of chemiluminescent signal for quantification. The immunoassay format described here supports the requirement for high throughput necessary for monitoring large numbers of samples in population-based studies. The optimized immunoassay was more sensitive than the conventional enzyme immunoassay in buffer (IC(50) = 0.1 and 2 microg/L, respectively). The mixed-mode solid-phase extraction used for sample preparation to reduce possible urinary matrix effects allowed the accurate measurement of 3-PBA levels as low as 1 microg/L. The automated chemiluminescent immunoassay described here is sensitive, simple to use, and more rapid than the previously reported standard microplate assay.
我们开发了一种灵敏的自动化竞争性化学发光免疫分析法，用于检测3-苯氧基苯甲酸（3-PBA），它是许多拟除虫菊酯类杀虫剂的常见代谢产物。该系统使用一种竞争性半抗原-蛋白质结合物，其已用吖啶酯标记作为化学发光探针，并使用包被有二抗的顺磁性颗粒进行分离。在免疫分析试剂和样品混合进行竞争性孵育步骤后，使用全自动系统将孵育后的混合物加载到输送比色杯中，便于随后对免疫复合物进行磁分离并测量化学发光信号以进行定量。本文所述的免疫分析形式满足了在基于人群的研究中监测大量样品所需的高通量要求。优化后的免疫分析法在缓冲液中比传统酶免疫分析法更灵敏（IC(50)分别为0.1和2微克/升）。用于样品制备以减少可能的尿液基质效应的混合模式固相萃取法能够准确测量低至1微克/升的3-PBA水平。本文所述的自动化化学发光免疫分析法灵敏、易于使用，且比先前报道的标准微孔板分析法更快。
