This protocol is for isolating monoclonal cell population by limiting dilution. To see the full abstract and additional resources, please visit the Addgene protocol page.Sample Data1lentiCas9-Blast was a gift from Feng Zhang (Addgene plasmid #52962) and is described in Improved vectors and genome-wide libraries for CRISPR screening. Sanjana NE, Shalem O, Zhang F. Nature Methods. 2014 Aug;11(8):783-4.