IR 783 is a heptamethine cyanine fluorescent probe for in vivo imaging of tumor cells. It displays excitation/emission maxima of 776/798 nm, respectively.

Instructions
I. Solution preparation
1. Preparation of mother solution: Dissolve IR-783 in anhydrous DMSO, DMF or ethanol to prepare a 10-50 mM stock solution.
Note: After the stock solution is aliquoted, store it at -20°C in the dark and it can be stably stored for at least 6 months.
2. Preparation of working solution: Dilute the stock solution with an appropriate buffer (such as PBS or cell culture medium) to a working concentration of 1-10 μM, and adjust the specific concentration according to experimental needs.
II. Operation steps
Cell staining
1. Grow cells to an appropriate density (such as 70-80% confluence).
2. Gently wash the cells with PBS to remove residual culture medium.
3. Add the diluted IR-783 working solution to ensure that the cells are completely immersed.
4. Incubate at 37°C in the dark for 20-30 minutes.
5. Washing: After incubation, remove the dye solution; wash the cells 2-3 times with PBS or fresh culture medium to remove unbound dye.
6. Fluorescence detection: Use a fluorescence microscope, flow cytometer or other fluorescence detection equipment for analysis.
The fluorescence excitation wavelength of IR-783 is 780 nm and the emission wavelength is 810 nm. It is mainly used for fluorescence imaging in the near-infrared region.
Notes:
1) IR-783 is light-sensitive and should be kept away from light as much as possible during operation.
2) Please wear gloves before use to avoid direct contact with skin or mucous membranes.
3) After the experiment is completed, data collection should be performed as soon as possible to obtain the best fluorescence signal.