About BCECF AM

BCECF-AM is a cell-permeant pH indicator in its acetoxymethylester (AM) form with a pKa (6.97). This form of the pH indicator passively crosses the intact, live cell membrane where the AM ester moeity is cleaved by instracellular esterases, retaining the probe inside. At low pH, the reagent is weakly fluorescent but increases in intensity with increasing pH. This probe can be used ratiometrically as the excitation spectrum shifts between 439 nm and 505 nm, pH depending. This probe has, therefor, a primary excitation peak at 505 nm and a secondary peak at 439 nm with an emission peak that remains constant at 524 nm.