Figure 2. Intrinsic alterations in the extracellular acidification rate and oxygen consumption rate are not coincident with the observed death resistant phenotype.
CC1, CC2, DR1, DR2, DR3, and DR4 cells were seeded in triplicate (104 cells/well) in XF24 24-well cell culture plates, and allowed to grow for 24 h at 37°C. Prior to analysis, the growth medium was removed from the plate and replaced with Seahorse assay DMEM supplemented with 25 mM glucose, and the cells were incubated at 37°C without CO2 for 1 h. The cell culture plate was placed in the Seahorse XF24 Analyzer and the ECAR was measured. (A) ECAR and (B) OCR values were normalized to cell number as assessed by calcein AM fluorescence. Fluorescence was measured using 485 excitation and 530 emission wavelengths on the Microplate Reader-Infinite® M1000. Data were expressed as ECAR (mpH/min/104 cells) or OCR (pmoles/min/104 cells), cell number was determined by calcein AM incorporation. Data are mean +/− SE of seven experiments (p < 0.05).