Real Thiol, a reversible reaction-based fluorescent probe, can quantitatively monitor the real-time glutathione dynamics in living cells.

Real Thiol (RT) shows ratiometric fluorescence responses with a wide dynamic range when reacting with Glutathione (GSH). Real Thiol and its GSH adduct (RT-GSH) show fluorescence maxima at 487 and 562?nm with excitation wavelengths at 405 and 488?nm, respectively. The Kd for the reaction between Real Thiol and GSH is 3.7?mM. The wide dynamic range of Real Thiol (1 to 10?mM) allows for monitoring of the GSH level changes in both directions in living cells. 10% of Real Thiol reacts with thiolated proteins while 90% of Real Thiol reacts with GSH [1].