Assay Method Information

Assay Name:  CYP MUX (3A4) RI
Description:  Compound dilutions and assay-ready plates were prepared on a TTP Labtech mosquito HTS. Assay conduction was fully automated on a customized Screening Platform from Caliper (now PerkinElmer) containing a Mitsubishi robotic plate handler, Liconic incubators, a Caliper Zephyr liquid handling workstation equipped with temperature-controlled deck positions, a Biotek MultiFlo dispenser and an Agilent PlateLoc heat sealer. Assay plates were Corning Costar 384 well PP plates. High throughput mass spectrometric readout was performed on a RapidFire 300 system coupled to an AB Sciex API 4000 triple quadrupole device. CYP isoform 3A4 was incubated in a separate reaction of 50 μL final volume. 25 μL of HLM (human liver microsomes, BD UltraPool 150, 0.25 mg/mL final concentration) and the respective substrate, testosterone (75 μM) for 3A4, in potassium phosphate buffer (100 mM, pH=7.4) were added to 250 nL of stamped compound solution (10 mM in DMSO). The reactions were started upon addition of 25 μL of a co-factor solution containing magnesium chloride (3.3 mM), glucose-6-phosphate (3.3 mM), glucose-6-phosphate dehydrogenase (1.4 units) and NADP (1 mM) in potassium phosphate buffer (100 mM, pH=7.4) and incubated on deck at 37° C. for 10 min. 8 μL of each reaction were transferred to the same readout plated filled with 48 μL of stop solution containing internal standards (concentration in final readout plate), 6-hydroxytestosterone-D7 (0.5 μM), 4′-hydroxydiclofenac-D4 (0.2 and dextrorphan-D3 (0.01 in acetonitrile with 0.5% formic acid. After heat sealing, plates were stored at −20° C. for at least 30 min, centrifuged and subjected directly to RapidFire/MS analysis.
Affinity data for this assay
 

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