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.

Calcein Red AM, a red-emitting derivative of the green fluorophore calcein AM, is a cell-permeable, non-fluorescent acetoxymethyl ester compound commonly utilized to assess cell viability and cytotoxicity. following intracellular esterase cleavage, the fluorescent product is retained in live cells and exhibits characteristic excitation and emission peaks at 560 nm and 574 nm, respectively.

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].