Ishikawa E, Hamaguchi Y, Imagawa M, Inada M, Imura H, Nakazawa N, Ogawa H
J Immunoassay. 1980;1(3):385-98. doi: 10.1080/01971528008058479.
An improved preparation of antibody-coated polystyrene beads for sandwich enzyme immunoassay of human thyroid-stimulating hormone (TSH) was described. Rabbit anti-TSH IgG was purified by eluting at pH 2.5 from a TSH-Sepharose column, diluted 3 or 9 fold with normal rabbit IgG and used for coating polystyrene beads by physical adsorption. In a sandwich enzyme immunoassay of TSH using rabbit (anti-TSH) Fab'-beta-D-galactosidase conjugate, beta-D-galactosidase activities specifically bound to thus prepared polystyrene beads in the presence of TSH was 2.8-6.3 fold higher than those bound to polystyrene beads coated with anti-TSH IgG before purification. A similar effect was observed when guinea pig anti-pork insulin IgG, rabbit (anti-human IgE) IgG and goat (anti-human IgE) IgG were treated at pH 2.5. This improvement may be based on a conformational change of Fc in IgG molecule which was caused by the treatment at pH 2.5. Other sandwich immunoassays such as fluoro- and radio-immunoassays may also be improved in the same way.
本文描述了一种用于人促甲状腺激素（TSH）夹心酶免疫测定的抗体包被聚苯乙烯珠的改进制备方法。兔抗TSH IgG通过在pH 2.5下从TSH-琼脂糖柱上洗脱进行纯化，用正常兔IgG稀释3倍或9倍，并通过物理吸附用于包被聚苯乙烯珠。在使用兔（抗TSH）Fab'-β-D-半乳糖苷酶缀合物的TSH夹心酶免疫测定中，在TSH存在下，与如此制备的聚苯乙烯珠特异性结合的β-D-半乳糖苷酶活性比与纯化前抗TSH IgG包被的聚苯乙烯珠结合的活性高2.8至6.3倍。当豚鼠抗猪胰岛素IgG、兔（抗人IgE）IgG和山羊（抗人IgE）IgG在pH 2.5下处理时，观察到类似的效果。这种改进可能基于pH 2.5处理引起的IgG分子中Fc的构象变化。其他夹心免疫测定，如荧光免疫测定和放射免疫测定，也可能以同样的方式得到改进。
