Western blot confirming the monospecificity of the antibodies used. Only bands at the expected position are observed with antibodies against the following proteins: PTFγ, 45 kDa (lane 1); TBP, 44 kDa (lane 2); RNA polymerase II large subunit, 240 kDa (lane 3); TFIIH p62, 62 kDa (lane 4); TFIIF RAP74, 74 kDa (lane 5); and p80-coilin, 80 kDa (lane 6). The antibody 8WG16 against the RNA polymerase II large subunit (lane 3) labels multiple bands due to phosphorylation of the protein.