Ram B P, Hart L P, Shotwell O L, Pestka J J
J Assoc Off Anal Chem. 1986 Sep-Oct;69(5):904-7.
Naturally contaminated corn and cottonseed samples were screened for aflatoxin B1 (AFB1) by a direct competitive enzyme-linked immunosorbent assay (ELISA). Samples were blended 5 min in an extraction solvent of methanol-water-dimethylformamide (70 + 29 + 1) and filtered. Filtrates were assayed by direct competition between AFB1 in the corn and cottonseed samples and AFB1-peroxidase conjugate for binding to specific antibody adsorbed to a solid phase microtiter plate. Standard curves prepared using the extract of AFB1-free corn and cottonseed samples, and extraction solvent only, showed negligible interference by the sample extract in the performance of ELISA. The AFB1 content in corn and dehulled cottonseed samples as determined by ELISA ranged from 7 to 422 micrograms/kg and 7 to 3,258 micrograms/kg, respectively. When ELISA estimates of AFB1 in corn were compared with values obtained by thin layer chromatography (CB method), the correlation coefficient (n = 10) was 0.95. Average interassay and subsample coefficients of variation for ELISA in corn were 21.4 and 22.0%, respectively. When ELISA estimates of AFB1 in cottonseed were compared with values obtained by liquid chromatography (Pons method), the correlation coefficient (n = 15) was 0.96. Using this ELISA, 36 duplicate sample extracts can be screened for AFB1 in less than 2 h.
采用直接竞争酶联免疫吸附测定法（ELISA）对天然污染的玉米和棉籽样品进行黄曲霉毒素B1（AFB1）筛查。将样品在甲醇 - 水 - 二甲基甲酰胺（70 + 29 + 1）提取溶剂中混合5分钟，然后过滤。通过玉米和棉籽样品中的AFB1与AFB1 - 过氧化物酶结合物之间的直接竞争，以结合吸附在固相微量滴定板上的特异性抗体，对滤液进行检测。使用不含AFB1的玉米和棉籽样品提取物以及仅提取溶剂制备的标准曲线表明，样品提取物对ELISA性能的干扰可忽略不计。通过ELISA测定的玉米和脱壳棉籽样品中的AFB1含量分别为7至422微克/千克和7至3258微克/千克。将玉米中AFB1的ELISA估计值与薄层色谱法（CB法）获得的值进行比较时，相关系数（n = 10）为0.95。玉米中ELISA的平均批间和子样本变异系数分别为21.4%和22.0%。将棉籽中AFB1的ELISA估计值与液相色谱法（庞斯法）获得的值进行比较时，相关系数（n = 15）为0.96。使用这种ELISA，可在不到2小时内对36个重复样品提取物进行AFB1筛查。
