Research on the Method of Developing Latent Blood Fingerprints on Non-porous Surface Based on Fluorescent Labeling Technology

In order to study the feasibility of using fluorescein to develop latent blood fingerprints based on fluorescent labeling technology and explore the optimal conditions for its development, we selected two cselected used fluoresceins (FITC fluorescein and DCFH-DA fluorescein) as the main research objects of this experiment, to design the method and procedure of developing latent blood fingerprints on non-porous surfaces with fluorescein, based on the principle of fluorescent labeling technology. On this basis, PBS buffer was used to change the pH environment of fluorescein solution, and acetone was used to dilute the two fluorescein solutions by 5 times, 10 times and 100 times, respectively, in order to explore the best developing conditions of latent blood fingerprints. The results showed that both FITC fluorescein and DCFH-DA fluorescein were effective in developing latent blood fingerprints on non-porous surfaces. The best conditions for FITC fluorescein to develop latent blood fingerprints on non-porous surfaces are: the developing time being 10 minutes, the pH environment value being 9.35, and the concentration being the original concentration; The best conditions for DCFH-DA fluorescein to develop latent blood fingerprints on non-porous surfaces are: the developing time being 20 minutes, a pH environment value being 13.01, and the concentration being the original concentration. Therefore, it is feasible for the fluorescence labeling technology to develop latent blood fingerprints on non-porous surface, but it is still necessary to further explore the preservation time of prepared fluorescein solution and the damage of DNA detection in blood fingerprints by this technology, and comprehensively analyze its practical application value.