CHEMBL5734571

Biological Assay: A fluorescent imaging plate reader (FILEX/FLIPR station; Molecular Devices) was used to monitor intracellular calcium levels using the calcium-chelating dye Rim-4 (Molecular Probes). The excitation and emission wavelengths used to monitor fluorescence were 470-495 nm and 515-575 nm, respectively. Cells expressing purinergic receptors P2X3 (human) or P2X2/3 (human) were plated at a density of 15,000 cells/well in collagen-coated 384-well plates approximately 20 hours before beginning the assay. On the day of the assay, 20 μl of loading buffer (Hank's balanced salt solution, 20 mM HEPES, 0.5 mM CaCl2, 0.5 mM MgCl2, 0.1% BSA, 5 mM probenecid, 10 mM D-glucose monohydrate, 2 μM Fluo-4, and 5 units/mL, hexokinase, pH=7.4) was added and cells dye-loaded for 90 min at 37° C. The dye supernatant was removed and replaced with 45 μl probenecid buffer (Hank's balanced salt solution, 20 mM HEPES, 0.5 mM CaCl2, 0.5 mM MgCl2, 0.1% BSA, 5 mM probenecid, 10 mM D-glucose monohydrate, pH=7.4). The test compound was added in a volume of 5 μl and allowed to incubate for 30 min at 37° C.