Evaluation of standard curves in the graded hemagglutination-inhibition method applied to quantitation of human immunoglobulins.
For accurate quantitation of human immunoglobulins A and B by graded hemagglutination inhibition, I have established standard curves. For IgA, plotting the inner diameter of the ring formed by sedimented erythrocytes vs the log of the antigen concentrations gives a straight line. Plotting the same parameters for IgG gives a hyperbolic line. These ratios between antigen concentration and ring diameter were constant for at least one year. Both undiluted and 10,000-fold diluted human serum may be quantitated by this method, depending only on immunoglobulin concentrations. Precision (CV) of the system, assessed in 35 patients' sera over the period of one year, ranged from 0.5 to 15.2% (mean 10%) for IgA and from 1.4 to 14.9% (mean 7.3%) for IgG.
D006385:Hemagglutination Inhibition Tests; D006801:Humans; D007070:Immunoglobulin A / Q000032:analysis; D007074:Immunoglobulin G / Q000032:analysis; D007136:Immunoglobulins / Q000032:analysis*
D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007136:Immunoglobulins