Apoprotein assays: radial immunodiffusion versus an immunoturbidometric technique

The measurement of apolipoprotein using radial immunodiffusion (RID) and Cobas-Bio immunoturbidometric assays is compared. Samples were obtained from 100 patients in a fiber-diet study. RID assays were performed using plates, standards, and diluent from Tago Inc. The immunonephelometric assays were performed on a Cobas-Bio with DENS program centrifugal analyzer. The correlation coefficient for the apolipoprotein Al was 0.90 and for apolipoprotein B was 0.91. The bias of the RID was to report higher values. The Cobas-Bio system affords the clinical laboratory with a reliable and cost-effective means for assessing these apolipoproteins.