The working principle of fluorescent agent is that the light emitted by xenon arc lamp is changed into intermittent light by light chopper and monochromatic light by excited monochromator, which is the excitation light of fluorescent substance. The fluorescence emitted by the fluorescent substance under the excitation light is changed into monochromatic fluorescence by a monochromator and then irradiated on a photomultiplier tube used for measuring samples, and the photocurrent generated by the fluorescent substance is amplified by an amplifier and then transmitted to a recorder.
Fluorescence spectrophotometer is an instrument used to scan the fluorescence spectrum emitted by liquid fluorescent markers. It can provide many physical parameters including excitation spectrum, emission spectrum, fluorescence intensity, quantum yield, fluorescence lifetime, fluorescence polarization and so on, and reflect the bonding and structure of molecules from many angles. By measuring these parameters, we can not only make general quantitative analysis, but also infer the conformational changes of molecules in various environments, so as to clarify the relationship between molecular structure and function. The excitation wavelength scanning range of fluorescence spectrophotometer is 190~650nm, and the emission wavelength scanning range is 200~800nm. It can be used for spectral scanning of liquid and solid samples (such as gel strips).