PF-06726304

Karpas-422 cells are plated in complete cell culture medium (100 μL/well) in a 96-well clear, V bottom polystyrene cell culture plate at a density of 2500 cells/well. The cells are then incubated for 2−3 h at 37 °C and 5% CO2. Compound dilution plates are prepared in 96-well clear, U-bottom polypropylene plates in 100% DMSO at 10 mM stock concentration in duplicate wells using an 11-point serial dilution (1:3 dilutions). Compounds are further diluted in growth medium, and 25 μL is added to each well of the cell plates. The highest compound concentration tested is 50 μM final, with a 0.5% final DMSO concentration. The plates are then incubated for 72 h at 37 °C and 5% CO2. At the end of the incubation period with compound, the plates are centrifuged at 2000 rpm for 5 min at room
temperature, and the medium is removed. Then 100 μL of acid-extracted solution is added to each well. The plates are shaken for 50 min at 4 °C to lyse the cells, and then 38 μL of neutralization buffer is added. The plates are then frozen at −80 °C. The next day, the plates are shaken at room temperature to thaw. Cell lysates (50 μL/well) are then transferred to ELISA plates. The plates are covered and incubated for 2.5 h at room temperature with constant slow-speed shaking. After incubation, the plates are washed seven times (300 μL/well) with 1× wash buffer. Then 100 μL of biotinylated trimethylhistone H3K27 detection antibody is added to each well and incubated for 2 h at room temperature with constant slow-speed shaking. After incubation, the plates are washed as described above. Horseradish peroxidase-linked antibody (100 μL) is added to each well and incubated for 60 min at room temperature with constant slow-speed shaking. After incubation, the plates are
washed. Finally, 100 μL of TMB substrate reagent is added to each well and incubated for 5 min at room temperature in the dark with slow shaking, after which 100 μL of stop solution is added to stop the reaction.