The effect of anti-Bcl-2-scFv-TAT on the level of Bcl-2 and on its interaction with Bax. The level of Bcl-2 protein was analyzed in RBL cells treated for various periods of time with either anti-Bcl-2-scFv-TAT or nonspecific scFv-TAT. After immunoprecipitation with anti-Bcl-2 antibody, Bcl-2 was identified by Western blotting (top row). The same immunoblot was exposed to anti-Bax antibody in order to determine the interaction between Bcl-2 and Bax (second row). The presence of scFv-TAT was visualized using anti-myc antibody (third row). Anti-actin was used as a loading control (fourth row).