Flow cytometric histograms of an MDR1(−)/LRP(−)/MRP1(−)/Efflux(+) AML case. (A) Dot plot showing laser-light characteristics of leukemic blasts (forward scatter, x-axis; side scatter, y-axis). (B) Leukemic blasts stained with the MDR1-specific antibodies, MRK16 (red) and MM4.17 (green), compared with the control (black). The leukemic blasts are negative for MDR1. (C and D) Leukemic blasts stained with the monoclonal antibodies LRP and MRPm6 (red) compared with the control (black). The blasts are negative for LRP and MRP1. (E and F) Flow cytometric histograms showing functional efflux of Rh123 and Di(OC)2 by leukemic blasts. Increasing cellular fluorescence (x-axis) plotted against cell number (y-axis). Functional efflux in the absence of the MDR1 inhibitor, CsA (green), is compared with efflux in the presence of CsA (red) and with the baseline (black). There is significant efflux of both Di(OC)2 and Rh123 that is blocked by CsA.
