pH modulation reverses cell death phenotypes. (A) 48-hr cell count of high-density culture in the presence of different concentrations of NaHCO3 (n=3). Medium was changed once at 24 hours. (B) Cell cycle analysis by Edu-PI in high-density and low-density culture with or without NaHCO3 (20mM) supplementation. (C) Caspase activation in high-density and low-density culture with or without NaHCO3 (20mM) treatment, analyzed by flow cytometry using CellEvent caspase 3/7 green detection reagent. (D) Mitochondrial membrane potential measured using JC-1. (E) Passaging efficiency of high-density cells maintained with or without NaHCO3 (20mM) supplement (n=3). Ri, rock inhibitor (Y27632 10µM). (F) Medium pH of high-density H9 culture with or without 1% (w/v) bovine serum albumin (BSA) (n=3). (G) 48-hr cell count of H9 high-density culture with or without BSA (n=3). HD, high-density. LD, low-density. Ctrl, control.