A unique nucleosomal PTM combination captured by ATRX-ADD MARCC. Relative amounts of different PTM states for selected histone peptide fragments from MARCC-enriched chromatin determined by qMS. Peptide sequence and modified lysine is labeled in the chart. Different PTM states for the same peptide sequence are represented by different colors. Relative quantity of the dominant state is labeled in the pie chart with unmodified state colored in gray and dimethylated or trimethylated state colored in red (red encircling lines mark the pooled dimethylation and trimethylation states). A high level of near stoichiometric enrichment of 4 PTM states (H3K4unmod, H3K9me2/3, H3K79unmod and H4K20me2/3) was identified from MARCC with ATRX-ADD. For AIRE-PHD MARCC, H3K4unmod but not the other three PTM states was enriched to 90%.