PROTOCOL FOR THE PREPARATION OF A SEGMENTAL LINEAR POLYACRYLAMIDE GRADIENT GEL - SIMULTANEOUS DETERMINATION OF LP[A], LDL, AND HDL PARTICLESIZES

We describe in this report a protocol for the preparation of a polyacr ylamide gel system (S-GGE 2.8/8.30) that consists of two linear gradie nts designed for the simultaneous determination of the diameters of LD L and HDL from whole plasma. The lower gel consists of an 8-30% linear gradient which is optimum for the resolution of HDL subfractions and the upper gel consists of a 2-8% linear gradient to allow for the reso lution of LDL and larger lipoprotein fractions such as Lp[a] and small VLDL. In contrast to other non-denaturing gradient gel systems which are based on protein staining, the present system uses lipid stain to specifically identify lipoproteins. This approach also allows the plas ma to be pre-stained with immediate visualization of the lipid bands b eing possible at the completion of the electrophoretic run. Using comm ercially available gel casting equipment, the present gradient gel sys tem can accommodate up to 21 lanes per gel. The inter-run and intra-ru n coefficients of variation for LDL particle size are 0.47 and 0.16%, respectively. The inter- and intra-run CVs for Lp[a] particle size are 0.92% and 0.89%, respectively. The inter-run and intra-run coefficien ts of variation for HDL2 and HDL3 particle size are 1.36% and 3.23%, r espectively.