Cre-mediated deletion of Rac1 sequence after pI-pC treatment. (A) Rac1 protein as detected by immunoblotting in WT and Rac1^–/–;Rac2^–/– washed RBC samples obtained weekly over the period of 2 to 5 weeks after induction. GAPDH used as loading control. Data representative of 12 samples tested per week. (B) Active, GTP-bound Rac1 determined by PBD pull-down assay 3 weeks after pI-pC treatment. Genotypes shown above. GAPDH used as loading control. Data representative of 3 experiments with similar results.