Transfection of leukapheresis cells by EP with mRNA. (A) EP transfection of the HV granulocyte-rich apheresis product with eGFP mRNA. Shown are dot plot graphs of FACS analysis of eGFP expression in naive cells and at 2 and 24 hours after transfection. Percentage of eGFP⁺ is indicated in the gated areas. (B) Optimization of transfection conditions assessing time (minutes) and temperature (temp.; room temp vs water ice) of incubation with eGFP mRNA before EP, and the effect of a red cell lysis step (+) before EP on the viability (top panel) and transfection efficiency (bottom panel) at 2 hours (blue) and 24 hours (red) after EP. The leftmost bars in graphs show the non-EP control (C/C). Incub, incubation; RBC, red blood cell; SSC, side scatter.