Figure 1. Response of ACTOne CALCR cell line & parental cell line to calcitonin. ACTOne CALCR 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 calcitonin. Ratios of the two readings (F/F0) are plotted in the figure. A. Dose response curve of calcitonin in ACTOne CALCR cell line. EC50 = 28.7 pM in the presence of PDE inhibitor Ro20-1724. B. Dose response curve of human calcitonin in Parental cells. In the presence of PDE inhibitor Ro20-1724, EC50 = 1.24 nM. Note. In CALCR cells, EC50 = 230 pM with rat Amy in the presence of Ro20-1724. In the parental cells, the response is negative when rAmy < 10 nM (in the presence of Ro20-1724)