Search and Browse
Download
Enter Data
|
Assay Method Information |
|
| | Cell-Based Functional Assay of Muscarinic Acetylcholine Receptor |
| Description: | For high throughput measurement of agonist-evoked increases in intracellular calcium, CHO-K1 cells stably expressing muscarinic receptors were plated in growth medium lacking G418 and hygromycin at 15,000 cells/20 μL/well in Greiner 384-well black-walled, tissue culture (TC)-treated, clear-bottom plates (VWR). Cells were incubated overnight at 37° C. and 5% CO2. The next day, cells were washed using an ELX 405 (BioTek) with four washes (80 μL) of assay buffer then aspirated to 20 μL. Next, 20 μL of 16 μM Fluo-4/acetoxymethyl ester (Invitrogen, Carlsbad, Calif.) prepared as a 2.3 mM stock in DMSO and mixed in a 1:1 ratio with 10% (w/v) Pluronic F-127 and diluted in assay buffer was added to the wells and the cell plates were incubated for 50 min at 37° C. and 5% CO2. Dye was removed by washing with the ELX 405 (four 80 μL washes of assay buffer) then aspirated to 20 μL. Compound master plates were formatted in an 11 point CRC format (1:3 dilutions) in 100% DMSO with a starting concentration of 10 mM using the BRAVO liquid handler (Agilent). Test compound CRCs were then transferred to daughter plates (240 nL) using the Echo acoustic plate reformatter (Labcyte, Sunnyvale, Calif.) and then diluted into assay buffer (40 μL) to a 2× stock using a Thermo Fisher Combi (Thermo Fisher Scientific, Waltham, Mass.).Calcium flux was measured using the Functional Drug Screening System (FDSS) 6000 (Hamamatsu Corporation, Tokyo, Japan) as an increase in the fluorescent static ratio. Compounds were applied to cells (20 μL, 2×) using the automated system of the FDSS 6000 at 4 s into the 300 s protocol and the data were collected at 1 Hz. At 144 s into the 300s protocol, 10 μL of an EC20 concentration of the muscarinic receptor agonist acetylcholine was added (5×), followed by the addition of 12 μL an EC8O concentration of acetylcholine at the 230 s time point (5×). Agonist activity was analyzed as a concentration-dependent increase in calcium mobilization upon compound addition. Positive allosteric modulator activity was analyzed as a concentration-dependent increase in the EC20 acetylcholine response. Antagonist activity was analyzed as a concentration-dependent decrease in the EC80 acetylcholine response. Concentration-response curves were generated using a four-parameter logistical equation in XLfit curve fitting software (IDBS, Bridgewater, N.J.) for Excel (Microsoft, Redmond, Wash.) or Prism (GraphPad Software, Inc., San Diego, Calif.). |
| Affinity data for this assay | |
|---|---|
| If you find an error in this entry please send us an E-mail | |
|
Home |
| |
Search |
| |
Deposit |
| |
SiteMap |
| |
About us |
| |
Email us |
| |
Info |
|
©2000 BindingDB. All rights reserved. |
|||||||||||||