[The determination of apolipoproteins Apo A-I and Apo B. A comparative study of methods]

We compared the analytical performance of a new in house developed ELISA and the commercial TurbiTime system for the determination of Apo AI and Apo B. Six dilutions of a poolserum, whose concentration had been determined by two other independent methods, were used as test material. A serum from which the apolipoproteins had been removed by immunadsorption was used as a diluent. Six specimens with known true values of Apo AI and Apo B were thus prepared. We established the analytical precision, the regression function and the correlation with respect to the true values and we constructed precision profiles and bias profiles. We found that the precision of turbidimetry is superior for the determination of Apo AI with concentrations less than 1 g/l. With Apo B both systems are nearly equivalent, the results of the turbidimetric methods were a little too low, the results of the ELISA a little too high. Below a concentration less than 0.5 g/l both methods are unreliable.