Western blot detection of 30 kDa SRAP in MCF-7 cells. Total proteins, extracted from MCF-7 breast cancer cells, were analyzed by western blot using 743A polyclonal anti-steroid receptor RNA activator protein (SRAP) antibody as described in the Materials and Methods section (743A). The antibody has been pre-incubated with its corresponding blocking peptide (743A + BP) or with an unrelated peptide (743A + Unr-P). In a parallel series of experiments, cells were transfected with an empty vector (Unt), SRA-RNAi or a construct encoding V5-tagged SRAP (SRAP-V5) as indicated in the Materials and Methods section. MCF = Michigan Cancer Foundation.