Fig. 1. Immunoblotting of HepG2 cell proteins fractionated by discontinuous sucrose gradient. HepG2 cell proteins were fractionated with detergent-free sodium carbonate discontinuous 5-40% sucrose gradients as described in the Materials and Methods. The 12 gradient fractions were concentrated with TCA and 50 µl sample of each fraction was loaded on 10% reducing SDS-polyacrylamide gel. After transfer on nitrocellulose, proteins were immunoblotted and detected by enhanced chemiluminescence. (A) SR-BI of control cells. (B) SR-BI of cells treated with 0.5% saponin (30 minutes at 4°C). C-F are from control cells: (C) caveolin-1; (D) clathrin heavy chain; (E) ABCA1; (F) L-FABP; (G) cytosolic NCEH; H, BSDL/CEL. The images are representative of three independent experiments.