Correlation of rhodamine efflux with MRK-16 staining. (A) Rhodamine efflux and MRK-16 staining was performed on SW 620 parental cells and cells selected in 10, 20, and 300 ng/mL Adriamycin, and designated as described in Fig 1, except that cells were not subjected to the CD56 labeling step. (B) Whole blood from each patient was obtained before initial treatment. Rhodamine efflux and MRK-16 staining were performed on mononuclear cells, and then stained with PE-labeled CD56 antibody. Designations as described in Fig 1. (C) The difference in rhodamine accumulation with and without exogenous PSC 833 (PSC − Control) and rhodamine efflux with and without exogenous PSC 833 (PSC/Efflux − Efflux) was plotted versus the difference between the MRK-16 histogram and the IgG1 negative control histogram for patients before receiving treatment (empty circles) and for the SW620 parental, Ad2, Ad5, Ad10, Ad20, and Ad300 cell lines (filled squares).
