[Nonradioactive iodine-labeled antibodies-inductively coupled plasma mass spectrometry for immunoassay]

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 spectrometry 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 (127 I) 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 microtiter plate and the I was detected by ICP-MS, the detection limit of the method was 0.12 mg x L(-1), relative standard deviation (n = 9) was less than 3% and the linearly dependent coefficient was 0.998 7. This system can also be used in analysis of other protein, nucleic acid and so on.