Comparison of different sandwich enzyme immunoassays for the quantitation of human apolipoproteins A-I and A-II.

Variants of a non-competitive enzyme immunoassay for human apolipoproteins A-I and A-II are described. The method developed is highly sensitive and highly specific. There is a good correlation between the reference technique (electroimmunoassay) and both apolipoprotein A-I and A-II assays (r=0.92). For the apolipoprotein A-I assay, seven simple treatments were studied. Two of these treatments (plasma plus Tween 20 and serum plus apo A-II) greatly increased the precision and the accuracy of the results. For the apo A-II measurement, no treatment of the samples is necessary, but plasma should be preferentially used rather than serum.