title: Crispr/Cas9-mediated screen of mus musculus: in-vitro-differentiated CD19+ total B cells
design: Nave B cells from Rosa26Cas9-GFP mice were cultured on 40LB cells with IL-4 and transduced with retroviruses encoding the pooled retroviral sgRNA library at a multiplicity of infection (MOI) of less than 0.2 to ensure that only one sgRNA was introduced into each cell. This was followed by puromycin selection for 2 days. The gene-edited cells were harvested and re-plated on fresh 40LB cells with IL-21 to induce plasma cell differentiation. After 4 days of culture with IL-21,  total B cells (GFP+BFP+) were sorted for deep genomic DNA sequencing to detect sgRNA sequences integrated in the genomic DNA.