非放射性碘标记-电感耦合等离子体质谱用于免疫分析研究

Nonradioactive Iodine-Labeled Antibodies-Inductively Coupled Plasma Mass Spectrometry for Immunoassay

研究了非放射性碘标记-电感耦合等离子体质谱免疫分析体系,该体系以兔抗大肠杆菌作为模型抗原,羊抗兔IgG蛋白为抗体,建立了一种新的免疫分析方法。实验中采用溴代琥珀酰胺(NBS)为氧化剂,实现非放射性127I标记羊抗兔IgG蛋白,探索了标记的最佳条件,标记率为63.12%;标记物在Sephadex G50柱上分离纯化后,研究了I-羊抗兔蛋白的稳定性,结果表明,标记物在4℃放置96 h后几乎没有碘脱落,并保持一定的活性。实验中采用聚苯乙烯96孔板作为固相载体进行免疫反应,以电感耦合等离子体质谱为检测手段,方法的检出限为0.12 mg.L-1,RSD(n=9)为3%;该体系也可适用于其他活性蛋白、核酸等的标记和分析。

In the present study, the system of nonradioactive iodine-labeled-antibodies linking inductively coupled plasma mass spectrometry for immunoassay was reported. The goat-anti-Escherichia coli and goat anti rabbit were considered as simulant antigen and antibody respectively in order to establish a new method of immunoassay by inductively coupled plasma mass spectrom- etry which has the advantage of high sensitivity, low detection limit and preferable linearity range. During the experiment, the N-bromosuccinimide, a mild oxidant, was used to oxidize the non-radioactive iodine （^127I） that labeled the protein. The method of nonradioactive iodine labeled protein was established and the best labeling condition was explored. The compound of I was purified by Sephadex G50 column chromatography, then the stability and activity were examined. The results showed that the labeling program was simple, reaction time was within two minutes, the labeling yield achieved 63. 12% and none of I shed from the compound after 96 hours. The simulant antigen and antibody reacted on polystyrene mierotiter plate and the I was detected by ICP-MS, the detection limit of the method was 0.12 nag · L^-1 , relative standard deviation （n=9） was less than 3% and the line- arly dependent coefficient was 0. 998 7. This system can also be used in analysis of other protein, nucleic acid and so on.