The optimisation of a novel iodide microassay and its application in an immunoassay for human antibody levels in serum.

Radioactive iodine has been used as an antibody label in many immunoassays. The feasibility of using non-radioactive iodine as a label was investigated. A microassay for iodide based on the Sandell-Kolthoff reaction was optimised. It was used to detect iodine-labelled antibody and successfully applied to the detection of human IgG in serum samples. The performance of this assay system compared with enzyme-linked immunosorbent assay using HRP was evaluated.