Gene pulser xcell electroporater

LCL cells were electroporated using a Gene Pulser Xcell Electroporater (BioRad) and 0.4 cm gap Gene Pulser electroporation cuvettes (BioRad). Briefly, 1 × 10⁷ LCL cells were resuspended in 250 μL RPMI-160 plus GlutaMax. To this media was added 65 μg of plasmid expressing ABE7.10, GFP, and the corresponding sgRNA targeting the C282Y mutation in the HFE gene. The mixture was added to a pre-chilled 0.4 cm gap electroporation cuvette and the cell/DNA mixture was incubated in the cuvette on ice for 10 min. Cells were pulsed at 250 V and 950 μF for 3 ms. Cells were transferred back on ice for 10 min, then transferred to 15 mL of pre-warmed RPMI-160 supplemented with 20% FBS in a T-75 flask. The next day, an additional 5 mL of media was added to the flask and cells were left to incubate for a total of 5 days. After incubation, cells were isolated by centrifugation, resuspended in 400 μL of media, filtered through a 40 μm strainer (Thermo Fisher Scientific), and sorted for GFP fluorescence using an FACSAria III Flow Cytometer (Becton Dickenson Biosciences). GFP-positive cells were collected in a 1.5-mL tube containing 500 μL of media. After centrifugation, the media was removed and cells were washed twice with 600 μL of 1× PBS (Thermo Fisher Scientific). Genomic DNA was extracted as described above.