intracellular esterase

5(6)-CFDA (5-(6)-Carboxyfluorescein diacetate) is a cell-permeant esterase substrate that can serve as a viability probe that measures both enzymatic activities, which is required to activate its fluorescence, and cell-membrane integrity, which is required for intracellular retention of their fluorescent product.

5-CFDA-AM is a cell-permeable esterase substrate used as an active probe to evaluate enzyme activity and cell membrane integrity. Electroneutral and able to enter cells at lower concentrations than CFDA, it undergoes intracellular hydrolysis by esterases to produce carboxyfluorescein, which possesses an extra negative charge, enhancing cellular retention [1].

5(6)-Carboxynaphthofluorescein diacetate serves as a fluorescent substrate in esterase assays, where it is cleaved by intracellular esterases, resulting in red fluorescence for enzyme activity measurement (Ex = 590 nm; Em = 645 nm) [1].