pHrodo Red (Cat. No. P35372) and Green (Cat. No. P35373) AM intracellular pH indicators are fluorescent probes used to measure pH in living cells. They are weakly fluorescent at neutral pH, but the fluorescence gradually increases as the pH decreases. These reagents can be used for quantitative analysis of cell cytosol in the pH range 4–9, pKa ∼6.5, with excitation/emission wavelengths of 560/585 nm (pHrodo Red) or 509/533 nm (pHrodo Green).

pHrodo Red and pHrodo Green pH indicator dyes are both photostable and suitable for multi-pass experiments. pHrodo Red is easy to use with a variety of blue, green, and far-red dyes and reporters (such as GFP, Fuo-4, Calcein, NucBlue, CellEvent Caspase 3/7 green, Mitosox Green, Mitotracker Deep Red, etc.) for multiplexing detection. pHrodo Green is easy to use with a variety of blue, red, and far-red dye reporters (such as Mitosox Red, CellEvent Caspase 3/7 Red, NucBlue, RFP, Mitotracker Deep Red, etc.) for multi-channel detection.

pHrodo Red and Green dyes are modified with AM ester groups, creating an uncharged molecule that can penetrate cell membranes. Once inside the cell, the lipophilic blocking group of the dye is cleaved by nonspecific esterases, resulting in a compound that remains in the intracellular space. At this time, the fluorescence intensity of the probe can indicate the pH value within the cell. Intracellular pH was then quantified using the Intracellular pH Calibration Buffer Kit (Cat. No. P35379).

pHrodo Red and Green AM intracellular pH indicator dyes are compatible with a variety of platforms such as traditional fluorescence microscopy, high content screening (HCS), flow cytometry and microplate fluorometric assays or high throughput Screening (HTS). These reagents are also compatible with widefield or confocal fluorescence microscopy, flow cytometry, fluorescence microplate readers, and high-content analyzers.