Fig. 3. SAMOSA-Tag: single-molecule chromatin profiling via tagmentation of adenine-methylated nuclei.

a, In SAMOSA-Tag, nuclei were methylated using the non-specific EcoGII m⁶dAase and tagmented in situ with hairpin-loaded transposomes. DNA was purified, gap-repaired and sequenced, resulting in molecules where the ends resulted from Tn5 transposition, the m⁶dA marks represented fiber accessibility and computationally defined unmethylated ‘footprints’ captured protein–DNA interactions. b, Length distribution for SAMOSA-Tag molecules from OS152 osteosarcoma cells. c,d, Average methylation from the first 1-kb of molecules (c) and unmethylated footprint size distribution (d) for the same data as in b. e, SAMOSA-Tag fibers at the amplified MYC locus. Predicted accessible and inaccessible bases are marked in purple and blue, respectively. Average SAMOSA accessibility is shown in purple; the matched ATAC–seq track is shown in light purple.