Generation of RNP edited A549-ACE2 and Huh7.5.1-ACE2/TMPRSS2 cells
All cells were dissociated into single cells using TrypLE Express (GIBCO), as described above, resuspended in culture media and counted. For A549-ACE2 transfections, 100,000 cells per reaction were used while for Huh7.5.1-ACE2/TMPRSS2 200,000 cells per reaction were used. Cells were pelleted by centrifugation at 200 xg for 5 min. Following centrifugation, cells were resuspended in transfection buffer according to cell type. 5 mL of cell solution was added to preformed RNP solution and gently mixed. Nucleofections were performed on a Lonza HT 96-well nucleofector system using program CM-120 and CM-104 for A549-ACE2 and Huh7.5.1-ACE2/TMPRSS2, respectively. All transfections were performed in Lonza SE buffer. Immediately following nucleofection, each reaction was divided evenly between two wells of a tissue-culture treated 96-well plate containing 100mL normal culture media.