Insulin Immunoassay by Back-Titration; Some Characteristics of the Technic and the Insulin Precipitant Action of Alcohol
Insulin Immunoassay by Back-Titration; Some Characteristics of the Technic and the Insulin Precipitant Action of Alcohol
复制标题
反滴定法胰岛素免疫测定；
DOI：
10.2337/diab.20.1.33
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发表时间：
1971
期刊：
影响因子：
7.7
通讯作者：
K. Sussman
中科院分区：
文献类型：
--
作者：
P. Wright;D. R. Makulu;D. Vichick;K. Sussman
对乙醇沉淀胰岛素及胰岛素免疫测定“反滴定法”的一些方面进行了研究。在没有胰岛素抗体的情况下，酒精对标记的胰岛素有明确的非特异性沉淀作用，这种作用在高浓度添加酒精或培养基中含有大量蛋白质时最为明显。这种放射性碘化胰岛素的非特异性沉淀不受高浓度未标记胰岛素的影响；这没有解释，但对分析系统没有影响。当后者在类似的短暂孵育条件下进行时，胰岛素测定的“反滴定”方法比“竞争性”技术更敏感和可重复性。“反滴定”方法被证明是针对胰岛素的，胰岛素原是唯一一种被测试并发现干扰分析系统的激素物质。该试验不受pH值变化的影响，可与抗猪或抗牛胰岛素血清混合使用，且不具有物种特异性。用人血浆得到的结果与用Morgan和Lazarow的方法得到的结果相当。预期的胰岛素量可以在大范围的血浆稀释度范围内恢复。对于常规目的，在一系列葡萄糖耐量试验中说明，“反滴定”方法已被证明是实用、快速和可重复性的。
Precipitation of insulin by alcohol and some aspects of the “back-titration” method of insulin immunoassay were investigated. In the absence of insulin antibodies, alcohol has a definite nonspecific precipitant action on labeled insulin, an action which is most marked when alcohol is added in high concentration or when the medium contains much protein. This nonspecific precipitation of radio-iodinated insulin is not affected by the presence of high concentrations of unlabeled insulin; this is not explained but has no effect upon the assay system. The “back-titration” method of insulin assay is more sensitive and reproducible than the “competitive” technic when the latter is carried out under similar brief conditions of incubation. The “back-titration” method is shown to be specific for insulin, proinsulin being the only other hormonal substance tested and found to interfere with the assay system. The assay is not affected by small changes in pH about neutrality, can be carried out with pooled anti-porcine or anti-bovine insulin serum, and is not species-specific. Results obtained with human plasma are comparable with those found by the method of Morgan and Lazarow. Expected amounts of insulin are recovered over a wide range of plasma dilutions. For routine purposes, illustrated in a series of glucose tolerance tests, the “backtitration” method has proved practical, rapid, and reproducible.