An ELISA for IgM titer of human serum

An ELISA for the measurement of serum immunoglobulins (Ig) of specific isotype is described which is reproducible, more sensitive than currently used methods and simple to perform. Data are presented to support the need to include a reference serum of known Ig content on the same plate as the specimen sera in order to compensate for plate-to-plate variability due to ambient conditions. This method should prove useful for monitoring changes in levels of specific Ig classes in the progression of diseases with immune system involvement or during a therapeutic regimen.