MULTICENTER EVALUATION OF A NOVEL QUANTIFICATION METHOD FOR RUBELLA AND TOXOPLASMOSIS ANTIBODIES

Antibody quantification by EIA is possible without a standard curve. F ollowing the so-called alpha method only one test dilution is used, th e resulting absorbance is corrected and the IU/ml will be calculated b y means of a mathematical formula. This new kind of a single point mea surement was evaluated in seven independent laboratories by comparison with commercial EIAs using a standard curve or a titer calibration li ne. For the quantification of IgG against rubella virus this study com prised 1,480 individual samples and three comparison EIAs. For IgG aga inst Toxoplasma gondii a total of 743 samples was evaluated in two com parison tests. The results obtained by the alpha method show a precisi on and accuracy more than sufficient for routine testings. Also the te chnical expenses and reagent costs were reduced. Prerequisites and lim itations are discussed against the background of the problem of immune status definition.