Figure 4.

Summary of ACM, SCG-DP-PCR (2^−ΔCt), and the Established 2^−ΔΔCt19 Methods

(Left) Schematic illustration of VCN determination with anti-CD19 CAR T cells harboring 2 CAR transgene copies under assumption of optimal PCR conditions. The figures and calculations refer to a haploid human genome to decrease complexity. Different qPCR strategies are illustrated. (A) Absolute standard curve method (ACM). (B) Relative quantification via the 2^−ΔCt method (SCG-DP-PCR). (C) Relative quantification via the 2^−ΔΔCt method. SCG, single copy gene; VCN, vector copy number; qPCR, quantitative polymerase chain reaction; Ct, threshold cycle; DP, duplex; EC, efficiency control. (Right) Corresponding required samples for VCN determination by different qPCR methods. Schematic illustration of samples required for different qPCR-strategies. (A) Absolute quantification via the standard curve method. (B) Relative quantification via the 2^−ΔCt method. (C) Relative quantification via the 2^−ΔΔCt method.