The eukaryotic genome is highly packaged to fit into the very limited nuclear space. As a result, access to genomic information is tightly regulated based on cellular state. What regions of the genome are accessible reveals a great deal about the state of the cell. ATAC-seq, or Assay for Transposase-Accessible Chromatin coupled with next-gen sequencing, is a technique to locate accessible chromatin regions.
As the name suggests, ATAC-seq is based on the use of a transposase called Tn5, which cuts exposed chromatin DNA into fragments. Because Tn5 is highly active, only a small number of unfixed cell nuclei is needed for the assay. Another benefit of using the Tn5 transposase is that it simultaneously attaches sequencing adapter to the ends of the produced DNA fragments, thereby facilitating sequencing library construction.
As input material, NUSeq needs 50,000 live cells to start. Cost for ATAC-seq library construction is listed on the Core Pricing page.
A. ATAC-seq basic scheme; B. An example of ATAC-seq signal. From Nature Methods 10, 1213–1218 (2013).