Abstract
Methodological problems of an enzyme-immunoassay kit employing the sandwich method were studied.
The insulin-antibody-coupled bead and the enzyme-coupled insulin antibody display sufficient capacities and high affinities for performing serum insulin determinations. The first reaction (antibodycoupled bead and serum insulin) was interfered with slightly by the presence of protein but the I. R. I. value obtained was corrected by the addition of a suitable concentration of serum protein to the standard insulin solution. The I. R. I. value obtained with this kit correlated well with that by radioimmunoassay in usual sera and was practically interchangeable. However, extra attention should be paid in the case of sera with markedly different concentrations of proteins and extracted insulin solutions. The I. R. I. obtained with this kit is nevertheless considered to be reliable and practically useful for routine I. R. I. determinations in clinical laboratories where the use of isotopes is restricted.
