Assay Report Card

ID: ALA3888296

Type: Binding

Description: In Vitro Inhibition of Ca Flux Assay: The 5HT3 antagonist activity of the compounds of the invention was determined by measuring the ability of the compounds to inhibit the calcium flux activity of 3HT3a receptor expressed in HEK-293T cells. HEK-293T cells were transfected with the 5HT3a expression construct using Xtreme Gene 9 (Roche) in 150 mm tissue culture treated plates and incubated for 24 hours at 37 °C. Cells were then split and plated at a density of 60K cells/well in poly-lysine coated, black 96-well plates with clear bottoms (BD BioSciences) and incubated overnight at 37 °C. Growth media was removed and cells loaded with 200 uL calcium indicator dye in HBSS containing 20 mM HEPES (Calcium 5 Assay kit, Molecular Devices) and incubated at 37 °C. for 1 hour. While cells were incubating, the 10× antagonist and agonist/antagonist addition plates were made. For 10× antagonist plate: half log serial dilutions (final concentrations range from 10−7 through 10−10 with the bottom well a negative, no ligand control) were made from test compounds in DMSO at a 1000× concentration and then diluted to 10× in HBSS/20 mM HEPES. For addition plate: 5HT was diluted to 100× in HBSS/20 mM HEPES (final concentration in the assay−216 nM) and 15 uL was added to each well of the addition plate, 15 uL of 10× compound was also added to the addition plate, and finally 120 uL of HBSS/20 mM HEPES (for a total of 150 uL). Cells were then removed from the incubator and equilibrated to room temperature for 10 minutes, then 22.5 uL of 10× test compounds were added in triplicate to the plates and incubated at room temperature for 10 minutes (Tropisetron was used as a positive control in every assay). Test plate and addition plate were loaded into the FlexStation III (Molecular Devices), and using the fluidics, 22.5 uL compound additions were made (at t=~17 seconds), and fluorescence was measured for 90 seconds, reading every 2.2 seconds.

Organism: Homo sapiens

Cell type: HEK-293T