Comparison of serum IgE determination by radioimmunoassay and by single radial immunodiffusion

Two commercially available methods of total serum IgE determination have been evaluated, viz: the radioimmunosorbent test (RIST) and the assay by single radial immunodiffusion (RID). RIST was found a suitable and rapid method for the wide range of IgE concentrations to be expected in the sera of an allergic population. The RID method has a lower limit of detection of about 1000 I.U./ml; over this value, both techniques provided statistically correlated results. However, for technological reasons RID was considered less suitable for routine application.