A simple micromethod for rapid assessment of the distribution of apolipoprotein C isoforms in very-low-density lipoprotein.

A simple and rapid isoelectric focusing method for quantifying Apo C isoforms of triglyceride-rich lipoprotein was developed. The very-low-density lipoprotein (VLDL) was isolated from 100 microL of EDTA plasma using a Beckman Airfuge ultracentrifuge. The delipidated VLDL was applied to an ultrathin flat acrylamide gel, and focused using a Bio-Rad Mini IEF Cell, for 1.5 h at a maximum of 500 V. Apo CII and Apo CIII in VLDL were resolved into four major bands, CIII0 (PI 4.91), CII (PI 4.78), CIII1 (PI 4.72), and CIII2 (PI 4.53). The method demonstrated within-run and between-run CVs of 2.7% to 11.9% and 4.4% to 12.2%, respectively. The relative percentage of C apoproteins and the ratio of CII to CIII found in VLDL from plasma of normal, chronic renal failure, and hyperlipidemic subjects agreed with previously published data.