Two immunofluorescent methods compared with a radial immunodiffusion method for measurement of serum immunoglobulins.

We found high correlations when the values for immunoglobulins G, A, and M, obtained from the analysis of a group of 50 or more human sera by a measured-time radial immunodiffusion method, were compared to values found by two new commercial immunofluorescent methods. The Fiax and the Immuno-Fluor systems make use of fluorescently labeled antibodies and solid-phase immunoadsorbents and offer simple, precise, and objective methods for immunoglobulin quantitation. The Fiax procedure is less time consuming than is the Immuno-Fluor and gives IgG and IgA concentrations that are in close agreement with those found by radial immunodiffusion and IgM values that are significantly lower than the radial immunodiffusion values. The IgG results determined by the Immuno-Fluor method compare well with the radial immunodiffusion results, uhile the IgA values are significantly higher and IgM values significantly lower than those obtained by radial immunodiffusion.