Using CellDrop to Count Isolated Nuclei Sponsored Content by DeNovix Inc.Mar 5 2021 The successful isolation of nuclei is an essential step in both ATAC-sequencing workflows and single cell RNA-sequencing. Successful library preparation requires users to ensure that all sample input is non-clustered and debris-free. Dual fluorescence counting using the CellDrop™ FL Automated Cell Counter is a useful tool, able to distinguish unlysed intact cells from isolated nuclei. Cluster analysis software provides an aggregation estimate to the user, with the resulting images allowing the user to verify that any debris has been effectively removed. Counting nuclei with AO/PI stain Acridine orange and propidium iodide (AO/PI) are utilized to confirm successful nuclei isolation. In conventional cell viability testing, the AO/PI dye combination will stain live cells so that these fluoresce green while staining dead cells so that these fluoresce red.