The FLS900 steady-state fluorescence spectrometer is used to test the blood in vitro radiated by the continuous laser. Variation components in the blood and the fluorescence characteristic decay with the time are given. Results show that when the blood is excited by the laser of 407 nm, the location of the fluorescence peak is unchanged, and the intensity of the emission peak at 605 nm is slowly decreased. But the fluorescence spectrum wave changes after 14 h, and eventually has a strong fluorescence peak at 474 nm. It is shown that the laser can obviously put off the decay time of the blood in vitro. After the laser continuously irradiates for a period of time, it can lead to the changes of cell morphology and accelerates the hemolytic process. The blood cell decay produces many fluorescent substances-the reduction of the nicotinamide adenine dinucleotide. The result provides a valuable reference to study the activity of blood cells and the functional abnormalities of the blood.
