Fig. 4

Demonstration of the Application of ddPCR in CAR T Cell Manufacturing. Vector copy number was measured in anti-GPC3-CAR T cells using different vector MOIs and spin transduction centrifuge speeds. Two different regions were assessed. a Average vector copy number measured in CAR T product produced using primers specific to the EF1a promoter region, plotted against MOI on a semi-log plot with a log-2 scaled X-axis. Data points are means of triplicates grouped by centrifugation condition. b Average vector copy numbers measured in CAR T cell products produced using primers against the scFv CAR region, plotted against MOI on a semi-log plot with a log-2 scaled axis. Data points are means of triplicates grouped by centrifugation condition. Centrifugation was observed to increase resultant average copy number at lower MOI, decreasing the slope of the semi-log lines. c Transduction efficiency was measured by flow cytometry for anti-GPC3-CAR T cells products and was plotted against MOI on a semi-log plot with a log-2 scaled X-axis. Values plotted are single data points observed in a CAR T cell product processed under two different conditions. d For each anti-GPC3-CAR T cell sample, vector copy number was plotted against transduction efficiency with linear fit. The data plotted was from a single anti-GPC3-CAR T product