Western blot was performed using histone extracts from HeLa cells (HeLa HE, 15 ug) and H3K4me3 polyclonal antibody (Cat # PAB14109) at dilution 1 : 500 in TBS-Tween + 5% skimmed milk.
Dot Blot was performed to test the cross reactivity of H3K4me3 polyclonal antibody (Cat # PAB14109) with the unmodified histone and with other histone modifications. Panel A shows the cross reactivity tests with unmodified histone H3 (Lane 1) and mono-, di- and tri-methylated lysine 4 of histone H3 (lanes 2-4). The antibody only recognizes the trimethylated lysine 4 (H3K4me3) (Lane 4). Panel B shows the cross reactivity tests with lysines 4, 9 and 27 of histone H3 (Lanes 1-3) and with lysine 20 of histone H4 (Lane 4). The antibody mainly recognizes trimethylated lysine 4 of histone H3 (Lane 1), although some cross reaction is observed with trimethylated lysine 20 of histone H4 (Lane 4).