Invitrogen™ SNARF™-4F 5-(and-6)-Carboxylic Acid, Acetoxymethyl Ester, Acetate - Special Packaging

Invitrogen™ SNARF™-4F 5-(and-6)-Carboxylic Acid, Acetoxymethyl Ester, Acetate - Special Packaging

The cell-permeant ratiometric pH indicator SNARF™-4F 5-(and-6)-carboxylic acid, acetoxymethyl ester, acetate (pK_a of ∼6.4) exhibits a significant pH-dependent emission shift from yellow-orange to deep red fluorescence under acidic and basic conditions, respectively. This pH dependence allows the ratio of the fluorescence intensities from the dye at two emission wavelengths - typically 580 nm and 640 nm - to be used for quantitative determinations of pH.