Fsp920 spectrofluorometer

The fluorescence spectra were investigated using a FSP920 spectrofluorometer (Edinburgh Instruments, the UK). The excitation and emission monochromator slits were both set to 2 nm, 3 nm, respectively. For the fluorescence emission spectra, the excitation wavelength for RhoSSCy was set to 480 nm and 640 nm, respectively. To measure the variation of fluorescent intensity of RhoSSCy with pH and thiols, the λ_ex was set to the same wavelength mentioned above and the emission wavelength (λ_em) was set to 576 nm and 765 nm, respectively.

N,N-Dimethylformamide (DMF), dichloromethane, dicyclohexylcarbodiimide (DCC), 4-dimethylaminopyridine (DMAP), 2',7'-Dichlorofluorescein diacetate (DCFH) and other chemical reagents were purchased from J&K Scientific. DMEM medium, fetal bovine serum (FBS) and kanamycin sulfate were purchased from Invitrogen Co. Ltd. All reagents were purchased from commercial suppliers and used without further purification. Solvents used were purified by standard methods prior to use. MCF-7, A549 and 293-T cells were kindly provided by the Cell Center of our institute. The buffer solutions were as follows: the high K⁺ buffer buffer containing 30 mM NaCl, 120 mM KCl, 1 mM CaCl₂, 0.5 mM MgSO₄, 1 mM NaH₂PO₄, 5 mM glucose, 20 mM HEPES (various pH values were adjusted by NaOH); phosphate buffered saline solution (PBS) containing 137 mM NaCl, 2.7 mM KCl, 4.3 mM Na₂HPO₄, 1.4 mM KH₂PO₄ (pH 7.4). ¹H NMR spectra were recorded on CD₃OD solutions using a Bruker AM-400 spectrometer. Mass spectra were obtained using a JMS-HX 110A/110A Tandem Mass Spectrometer (JEOL). UV-Vis spectra were obtained using a Scinco 3000 spectrophotometer (1 cm quartz cell) at 25 °C. Fluorescence spectra were recorded on FSP920 spectrofluorometer (Edinburgh Instruments, the UK)). Deionized water was used to prepare all aqueous solutions.