Figure 4: Isolation and identification of lipid rafts in matched HCC and ANT tissues in different histologic grades. (a) Membrane preparations after centrifugation to isolate lipid rafts as described in Section 2. Lipid rafts are mainly in fractions 5 and 6 appearing as an opaque band. Representative image shows an expanded lipid raft collar in HCC samples compared to ANT. (b) Equal volumes of the gradient fractions shown in (a) are analyzed by SDS-PAGE and blotted with caveolin-1 and flotillin-1. As the lipid raft resident proteins, caveolin-1 and flotillin-1 are mainly presented in fractions 5 and 6. All results are representative of at least three independent experiments.