Fig. 2

BE-FLARE facilitates reciprocal enrichment of co-edited cells. a Enrichment for BFP editing by selection for EGFR T790 M co-editing. PC9 cells stably expressing the BE-FLARE reporter were co-transfected with a construct expressing BE3 and gRNAs targeting EGFR T790 and BFP. Cells were treated with 100 nM gefitinib 72 h after transfection to select for EGFR T790 M mutants. GFP-positive cells were quantified by flow cytometry 4 days after addition of gefitinib. b Quantification of three independent experiments from (a), with each data point shown and mean represented as a bar. Unpaired Student’s t test; ***P < 0.001. c Sanger sequencing of the EGFR T790 locus from dual EGFR and BE-FLARE base edited cells after gefitinib selection. Percentage editing was estimated from sequencing chromatograms using EditR [31]. d Enrichment for EGFR T790 M editing by selection for BFP co-editing. PC9 cells stably expressing BE-FLARE were co-transfected as above. Cells were mock-sorted (all viable cells) or sorted for GFP expression by FACS 72 h after transfection, and 100 nM gefitinib was added 24 h later. Cell growth was quantified by Incucyte. Data are representative of three independent experiments. Raw data can be found in Additional file 2