CHEMBL5737416

Homogenous Time-Resolved Fluorescence (HTRF) Assay for Direct cAMP Measurement: The HTRF assay was carried out using a two-step protocol essentially according to the kit manufacturer's instructions, in 20 L total volume per well in 384-well plate format (ProxiPlates; PerkinElmer, Fremont, Calif.; catalog #6008280). To each of the experimental wells was transferred 1500 recombinant CHO-K1 cells in 5 μL phosphate buffered saline containing calcium chloride and magnesium chloride (PBS+; Invitrogen, Carlsbad, Calif.; catalog #14040) supplemented with IBMX (250 μM) and rolipram (20 μM) (phosphodiesterase inhibitors; Sigma-Aldrich, St. Louis, Mo.; catalog #15879 and catalog #R6520, respectively), followed by test compound in 5 μL compound buffer (PBS+supplemented with 10 μL NKH477 (water-soluble forskolin derivative; SignaGen Laboratories, Gaithersburg, Md.; catalog #PKI-NKH477-010)) or 5 L compound buffer. The plate was then incubated at room temperature for 1 h. To each well was then added 5 μL cAMP-d2 conjugate in lysis buffer and 5 μL Cryptate conjugate in lysis buffer according to the kit manufacturer's instructions. The plate was then further incubated at room temperature for 1 hour, after which the assay plate was read.