Assay Method Information

Assay Name:  Inhibition Assay
Description:  The dose dependent inhibition of OCT2 mediated uptake of a model substrate 14C-Tetraethylammonium (TEA) by test compounds was studied in wild-type and OCT2-transfected MDCKII cells at 7 concentrations from 0.014 μM to 10 μM.MDCKII cells were maintained in minimal essential medium (MEM) with 1% Pen/Strep, 10% fetal bovine serum, and 0.25 mg/mL hygromycin B in an incubator set at 37° C., 90% humidity and 5% CO2. 24 hours prior to assay, media containing 5 mM sodium butyrate were added to MDCKII cells in flasks, and cells were grown to 80-90% confluence. On assay day, cells were trypsinized and resuspended in Krebs-Henseleit Buffer (KHB), pH 7.4 at 5×106 million cells/mL. Cells were preincubated for 15 min in assay plate before addition of test compound or substrate.Test compounds were serially diluted in DMSO and then spiked (2 μL) into in 0.4 mL KHB buffer containing wild-type or OCT2-transfected cells and incubated for 10 minutes. Assay was initiated with the addition of 0.1 mL of 100 μM 14C-TEA in KHB buffer (20 μM final concentration after mixing). The concentration of TEA is based on the Km. After 10 minutes of incubation, the assay mixture was quenched with addition of 0.5 mL of ice-cold 1×PBS buffer. Samples were then centrifuged at 1000 rpm for 5 min and supernatants were removed. Wash steps were repeated four times with ice-cold PBS. Finally, the cell pellets were lysed with 0.2N NaOH and let sit at room temperature for at least 30 min to ensure complete lysis.
Affinity data for this assay
 

If you find an error in this entry please send us an E-mail