Intracellular Chloride Measurement Protocol

Intracellular Cl⁻ was measured as previously described [11 (link)]. Cells were plated in collagen-coated 96-well plates. Cells were loaded for 1 h with the Cl^—sensitive fluorescent dye, N-(ethoxycarbonylmethyl)-6-methoxyquinolinium bromide (MQAE) (Dojindo, Kumamoto, Japan) in Hank’s Balanced Salt Solution (HBBS) (110 mM NaCl, 3 mM KCl, 1.2 mM MgSO₄, 1.8 mM CaCl₂, 4 mM Na acetate, 1 mM Na citrate, 6 mM D-glucose, 6 mM L-alanine, 1 mM NaH₂PO₄, 3 mM Na₂HPO₄, 25 mM NaHCO₃). After loading, cells were washed thrice, and fluorescence was measured on a FLUOstar OPTIMA-6 (BMG Labtech) using 350 nm excitation and 460 nm emission.