Fig. 6. Western blot analysis of histone content in wild-type and demethylated ES cells. Equivalent amounts of cellular protein extracted from wild-type (J1) and Dnmt1^C/C (c/c) ES cells were loaded onto SDS polyacrylamide gels and stained with Coomassie Blue to confirm equal loading. Equivalently loaded lanes were transferred to membranes for western blot analyses using antibodies specific for the N-terminal tail of histone H2B, macroH2A and modification-state-specific antibodies that recognize histone H3 trimethylated at lysine 27 (methyl-H3K27), lysine 9 (methyl-H3K9) or lysine 4 (methyl-H3K4).