Kikutani M, Ishiguro M, Kitagawa T, Imamura S, Miura S
J Clin Endocrinol Metab. 1978 Nov;47(5):980-4. doi: 10.1210/jcem-47-5-980.
An enzyme-linked immunoassay was applied to the determination of hCG, a glycoprotein hormone usually assayed by RIA. For this purpose, an enzyme hormone conjugate was prepared by reacting hCG with beta-D-galactosidase (beta-Gal.) of E. coli in the presence of N-(m-maleimidobenzoyloxy) succinimide (MBS) as coupling reagent. The conjugate, after purification by affinity and gel chromatographies, was shown to exhibit sufficient enzyme activity and immunoactivity. The immunoassay of hCG was performed by the double antibody method and, using this assay, 0.4-250 mIU/ml hCG were detectable. This was about 10 times as sensitive as the RIA. Difficulty was experienced when this method was utilized for the determination of hCG in plasma samples from patients. Since the presence of the plasma may have affected this assay method, the following improvements were made: 1) the same volume of hormone-free plasma was added to the standard solutions of hCG, and 2) the volume of plasma sample was 10 microliter. The performance and validity of this assay were comparable to the RIA using [125I]hCG as tracer. The dose-response curves of both assay have the same slope and there was no significant difference between the values (correlation coefficient, Y = 0.96X + 1.53).
采用酶联免疫分析法测定人绒毛膜促性腺激素（hCG），这是一种通常用放射免疫分析法（RIA）检测的糖蛋白激素。为此，在作为偶联试剂的N -（间 - 马来酰亚胺苯甲酰氧基）琥珀酰亚胺（MBS）存在下，使hCG与大肠杆菌的β - D - 半乳糖苷酶（β - Gal.）反应，制备酶 - 激素偶联物。经亲和层析和凝胶层析纯化后的偶联物显示出足够的酶活性和免疫活性。hCG的免疫分析采用双抗体法进行，使用该方法可检测到0.4 - 250 mIU/ml的hCG。其灵敏度约为放射免疫分析法的10倍。将该方法用于测定患者血浆样本中的hCG时遇到了困难。由于血浆的存在可能影响了该检测方法，因此进行了以下改进：1）向hCG标准溶液中加入相同体积的无激素血浆；2）血浆样本体积为10微升。该检测方法的性能和有效性与以[125I]hCG为示踪剂的放射免疫分析法相当。两种检测方法的剂量 - 反应曲线斜率相同，数值之间无显著差异（相关系数，Y = 0.96X + 1.53）。
