Protein - DNA complexes were then
immunoprecipitated overnight with polyclonal Oct4 antibody (sc - 9081, Santa Cruz Biotechnology), a mix of monoclonal Oct4 antibodies (BD Transduction Labs, Santa Cruz Biotechnology, Chemicon), or normal serum controls (Pierce) on a rotator at 4 °C.
For this protocol, samples were lysed in 1 × RIPK2 lysis buffer [50 mM Tris (pH 7.5), 0 mM MgCl2, 1 % Triton X-100, 1 mM dithiothreitol, 1 mM EDTA, 1 mM EGTA, with freshly added 1 mM β - glycerophosphate and protease inhibitors (phenylmethylsulfonyl fluoride and aprotinin)-RSB- and
immunoprecipitated overnight using 1.5 μg rabbit anti-RIPK2 antibody.