SDS-PAGE/immunoblot analysis of recombinant HIV-1 CA. NiCo21(DE3) E. coli were transformed with pSA-Hp24-6His vector and grown at 30°C for 6 hours, either induced with 0.4 mM IPTG, or un-induced. Cells were processed as described in Methods and labeled as whole cell lysate (WCL), insoluble fraction (IS), and soluble fraction (S). Eight microliter of each sample (WCL, IS, S) was mixed with 4X loading dye and electrophoresed on 12% gel. Proteins were transferred to nitrocellulose membrane and stained with MemCode™ Reversible Protein Stain Kit (Pierce) and photographed (left panel). Membrane was then destained and subjected to immunoblot analysis using primary anti-p24 antibody and secondary anti-Mouse antibody. Membrane was developed using enhanced chemilumenscent reagent (Pierce) and image was captured (right panel). Lane M1, BenchMark Pre-stained protein ladder; Lanes WCL, whole cell lysate; Lanes IS, insoluble fraction; Lanes S, soluble fraction; Lane M2, MagicMark XP Western Protein Standard.