Figure 1. Response of ACTOne Prostaglandin D Receptor 2 cell line & parental cell line to prostaglandin D2. ACTOne PTGDR2 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 prostaglandin D2. Ratios of the two readings (F/F0) are plotted in the figure. A. Dose response curve of prostaglandin D2 in ACTOne PTGDR2 cell line. EC50 = 0.62 nM in the presence of PDE inhibitor Ro20-1724. B. Parental cells do not respond to prostaglandin D2.