Fig. 2. Effect of Triton X-100 treatment and cholesterol depletion on TfR2 and TfR1 cell membrane expression. K562 cells were labeled with anti-TfR1, anti-TfR2 or anti-CD81 mAbs (left, middle and right panels, respectively) and the fluorescence was measured before (C) and after (TX-100) 5 minutes of detergent treatment. Depletion of plasma membrane cholesterol was achieved by incubation with methyl-ß-cyclodextrin (MBCD) before antibody labeling and TX-100 treatment.