RT Journal Article SR Electronic T1 Efficient transcription-coupled chromatin accessibility mapping in situ JF bioRxiv FD Cold Spring Harbor Laboratory SP 2020.04.15.043083 DO 10.1101/2020.04.15.043083 A1 Steven Henikoff A1 Jorja G. Henikoff A1 Hatice S. Kaya-Okur A1 Kami Ahmad YR 2020 UL http://biorxiv.org/content/early/2020/09/18/2020.04.15.043083.abstract AB Chromatin accessibility mapping is a powerful approach to identify potential regulatory elements. In the popular ATAC-seq method, Tn5 transposase inserts sequencing adapters into accessible DNA (‘tagmentation’). CUT&Tag is a tagmentation-based epigenomic profiling method in which antibody tethering of Tn5 to a chromatin epitope of interest profiles specific chromatin features in small samples and single cells. Here we show that by simply modifying the tagmentation conditions for histone H3K4me2/3 CUT&Tag, antibody-tethered tagmentation of accessible DNA sites is redirected to produce accessible DNA maps that are indistinguishable from the best ATAC-seq maps. Thus, DNA accessibility maps can be produced in parallel with CUT&Tag maps of other epitopes with all steps from nuclei to amplified sequencing-ready libraries performed in single PCR tubes in the laboratory or on a home workbench. As H3K4 methylation is produced by transcription at promoters and enhancers, our method identifies transcription-coupled accessible regulatory sites.Competing Interest StatementThe authors have declared no competing interest.