Figure 1. Response of ACTOne PTGER2 cell line & parental cell line to PGE1. ACTOne PTGER2 cells and parental cells (AG-10200-200) were plated overnight in 20 ml culture medium on a BD Biocoat 384 well plate. The next day, cells were dye-loaded with 20 ml/well of 1X Dye-loading solution (ACTOne Membrane Potential Assay Kit). After 2 hours of incubation at room temperature, two readings were obtained prior to and 30 min after the addition of PGE1. Ratios of the two readings (F/F0) are plotted in the figure. A. Dose response curve of PGE1 in ACTOne PTGER2 cell line. EC50 = 13.0 nM in the absence of PDE inhibitor Ro20-1724. B. Parental cells do not respond to PGE1 in the absence of PDE inhibitor Ro20-1724.