Turbidimetric assay of apolipoprotein A-II

A turbidimetric assay for the quantification of apolipoprotein A-II in serum is described. Its adaptation for the Cobas Bio Analyser (Hoffmann La Roche) is reported. Regression analysis of apolipoprotein A-II values measured by turbidimetry revealed a good measure of agreement with the data obtained by radial immunodiffusion (RID) (r = 0.90, y = 0.97x + 0.021, n = 100) as well as with data obtained by immunonephelometry (r = 0.838, y = 0.925x + 0.029, n = 34). A variation coefficient of 3.2% (n = 18) was found in relation to the precision in the series and a variation coefficient of 3.5% (n = 36) in relation to day to day precision.