| Assay Method Information | |
| | IP-One Assay |
| Description: | In a typical experiment, the OXI and OX2 receptor agonist activity is determined in accordance with the following general experimental method. Chinese hamster ovary (CHO) cells expressing human 0X1R and/or the human 0X2R were grown in Iscove s modified DMEM containing glutaMAX , 1% G418, 100 U/mL penicillin, 100 pg/mL streptomycin and 10 % heat-inactivated qualified fetal bovine serum (FBS). The OX2R cells were seeded at 10,000 cells/well/50 μL and the OX1R cells were seeded at 20,000 cells/well/50 μL into 384-well white tissue culture plates (Greiner; cat# 781080). All cell/media reagents were from GIBCO-Invitrogen Corp. The seeded cell plate(s) were incubated at 37°C with 5% CO2 and 85% humidity for 20-24 hours. On the day of the assay, assay-ready compound plates were prepared using an acoustic liquid handler (ECHO; Labcyte), which dispensed sufficient volume of test compound stock (10 mM in DMSO) or 100% DMSO to prepare 10 point, -log dilutions in a final volume of 202.5 nL/well in all test wells of a 384-well diamond plate (Labcyte). Following completion of assay -ready plates, importantly, the next three steps were performed with minimal delay: 1) 20 pl of lx stimulation buffer was added to the compound plate using a Multidrop Combi (small cassette, Thermo Fisher Scientific cat# 24073290); 2) culture medium was removed from the cell plate using the Bluewasher plate washer (gentle spin; BlueCatBio); 3) 14 p 1 of compound/stimulation buffer mixture was added to the cell plate using a Bravo liquid handler (Agilent) prior to incubating cell plates at 37°C with 5% CO2 and 85% humidity for 1 or 2 hours (OX1R and OX2R, respectively). During this incubation, IP-one detection reagents were prepared (38: 1:1 lysis buffer: D2:AB-cryptate reagents). Six μL of mixed detection reagents were added to the cell plate using a Multidrop Combi (small cassette, Thermo Fisher Scientific cat #24073290) and incubated 60 minutes at room temperature in the dark. Fluorescence signal was detected using an Envision plate reader (Perkin Elmer) [LANCE/DELFIA Dual Enh (Em: APC 665; Ex: Cy5 620)].For each compound, data were fit to a four parameter logistic fit (Activity Base software) and the EC50 was reported as the inflection point of the resulting curve. Percent effect for each test compound was determined as the percentage of sample raw value/mean max effect, where the mean max effect was derived from the mean raw value of 32 control wells per assay plate (using Orexin A (cat# 003-30) at 1 μM for human OX1R and a reference compound at 1 uM with 100% activity previously established by comparison to Orexin A for human OX2R). The intrinsic orexin receptor agonist activity of a compound which may be used in the present invention may be determined by these assays. |
| Affinity data for this assay | |
|---|---|
| If you find an error in this entry please send us an E-mail | |