MODIFICATION OF PROCEDURE OF HALES AND RANDLE FOR RADIOIMMUNOASSAY OF INSULIN

A modification of the radioimmunoassay for insulin (method of Hales and Randle) is described. Separation of precipitated/antibody-bound insulin from free insulin was achieved by centrifugation instead of filtration. Addition of a carrier-immunoprecipitate relatively diminished possible losses by decantation during the washing steps. Sensitivity (10 μU/ml), precision (λ= 0.067-0.314) and reproducibility are comparable with some other published data. The modification avoids the difficulties due to the filtration procedure in the use of commercially available test-kits for the radioimmunoassay of insulin. © 1969 Springer-Verlag.