Assay Report Card

ID: ALA3888033

Type: Binding

Description: FLIPR Assay: The bioactivity of compounds is tested in a fluorometric imaging plate reader (FLIPR: Molecular Devices) using engineered CHO-K1 cells expressing the human CXCR3A coupled to a G protein (Galpha(16)). Cells are plated the day prior to bioassay in F12 medium supplemented with 10% FBS and G418 and hygromycin antibiotics to maintain recombinant selection. At the day of bioassay, cells are washed and dye loaded for one hour with Fluo-4-AM (Invitrogen) in Hanks Balanced Salt Solution (Invitrogen), buffered with 20 mM Hepes at pH 7.4 and sodium bicarbonate (0.015%), containing 5 mM probenecid. This buffer, but lacking the dye and containing probenecid at a concentration of 2.5 nM, is also is used for washing steps (wash buffer); or lacking both dye and probenecid but supplemented with 0.1% BSA for compound dilution steps (dilution buffer). Cells are washed free of excess dye and 60 microliter of wash buffer is added. Stock solutions of test compounds are made up at a concentration of 10 mM in DMSO, and serially diluted in dilution buffer to concentrations required for inhibition dose response curves. After a 10 minute incubation period at 37° C., 10 microliters of each compound dilution are transferred from a compound plate to the plate containing the recombinant cells in the FLIPR instrument according to the manufacturer's instructions. Following basal readings, 10 microliter CXCL10 agonist at a concentration of 20 nM (from Peprotech) is added, again using the FLIPR instrument. Changes in fluorescence are monitored before and after addition of the test compounds.

Cell type: CHO-K1