Theoretical analysis of the accuracy of calibrated immunoassays for measuring antibody concentration.

The accuracy of calibrated immunoassays for measuring antibody concentration was analysed from a theoretical perspective. The study shows that there are theoretical limits on the accuracy of antibody immunoassays, which are determined by the affinity of the standard and unknown antibodies and the conditions chosen for the assay. As a result of these limits, calibration of an immunoassay with a standard antibody does not automatically ensure accurate measurements of antibody concentration. Extremely large errors may develop in affinity-dependent assays when the affinities of the standard and unknown antibodies are different. Assay conditions and the affinity of the standardizing antibody must be chosen carefully to measure antibody concentration accurately.