Naph-EA-mal (Thiol-green 1) is a rapid detect and ultrafast turn-on thiol fluorescence probe for protein labeling and bioimaging. Naph-EA-mal (Thiol-green 1) can be used to detect thiols in living cells, label the protein thiols, quantify the concentration of total thiols in cell lysate, and determine the reversible protein thiols oxidation in fixed cells[1]. Ex: 488 nM; Em: 540 nM.

Imaging thiols in living cells[1]Hep G2 cells incubated with Naph-EA-mal (Thiol-green 1) (1 µM;5 mins), and strong green fluorescence can be observed. When cells are preincubated the cells to block the intracellular thiols with NEM (a thiol block reagent; 100 µM), a weaker fluorescence is observed in cells[1].Monitoring thiol-disulfide levels in fixed cellsDue to the majority of cellular thiols are present in the reduced form, Naph-EA-mal (Thiol-green 1) (10 µM) induces strong fluorescence in Hep G2 cells. After diamide treatment, fluorescent signal sharp dimed is observed[1].The Hep G2 cells, oxidized by diamide (200 µM; 30 min), are fixed by 70% EtOH and the remaining free thiols are blocked by NEM (100 µM). then The cells are further treated with TCEP (5 mM) followed by addition of the Naph-EA-mal (Thiol-green 1) (10 µM). The green fluorescent signal is detected again[1]

[1]. Jinyu Sun, et al. An ultrafast turn-on thiol probe for protein labeling and bioimaging. Analyst