Western blot analysis of biotinylated P. chabaudi PESAs. P. chabaudi infected erythrocytes were obtained from two infected CBA mice by heart puncture and cultured for 6 hours to allow ring stage parasites to mature. Panel A. Western blotting of P. chabaudi infected erythrocyte membrane extracts prepared by osmotic lysis. Biotinylated proteins were detected using horseradish peroxidase-conjugated streptavidin. Solid arrowheads highlight infected erythrocyte-specific biotinylated proteins. Panel B. Silver stained duplicate gel of that shown in Panel A to confirm the cell surface specificity of trypsinization. U: uninfected erythrocyte, I: infected erythrocyte.