During optical imaging experiments, mice are anesthetized using a gaseous anaesthesia system based on isoflurane mixed to oxygen and nitrogen protoxide and placed inside Explore Optix. A prescan image is acquired before labelled probe administration. Different routes of administration can be performed: intraperitoneal, intravenous, intratumor, subcutaneous, etc.
The animals are monitored at multiple time points and in all imaging experiments, a 670 nm pulsed laser diode with a repetition frequency of 80 MHz and a time resolution of 12 ps light pulse is used for excitation. Fluorescence emission is collected at 700 nm and detected through a fast photomultiplier tube and a highly sensitive time-correlated single-photon counting system. Laser power, integration time and scan step are optimized according to the emitted signal. The data are recorded as temporal point-spread functions, and the images are reconstructed as fluorescence intensity and fluorescence lifetime.