High-Resolution ATAC-Seq Analysis of Frozen Clinical Tissues.

The ATAC-seq method enables the genome-wide analysis of accessible chromatin revealing transcriptionally active and poised regulatory elements. The ATAC-seq analysis of clinical specimens at a single-cell resolution reveals the cellular composition of the tissue contributing to the understanding of intra-tissue heterogeneity. Here we describe our method for nuclei isolation from frozen specimens with wide applicability across tissue types, producing nuclei suitable for a number of molecular profiling methods including ATAC-seq in bulk and at a single-cell resolution.