The identiifcation of body lfuid and their tissue resource is an important part of forensic medicine research. Conventional methods have imperfections like high false positive rate and may destroy biomaterial, which should be replaced by a new conifrmatory test. Highly-differentiated cells express speciifc mRNA molecules that can be used for body lfuid identiifcation. These mRNA markers can identify body lfuids like peripheral blood, menstrual blood, semen, saliva, vaginal secretion, skin-contact stains. This method have favorable sensitivity, speciifcity and can be detected after years, made it a ideal way to identify current body lfuids in the future. This review focus on the application of mRNA in body lfuid identiifcation and tissue resource.

Objective Using circRNA detection technology to explore the feasibility of the application of circRNA molecules in the identification of body fluids. Methods Prepare three kinds of body fluid samples: semen, saliva and vaginal secretions. Total RNA was extracted from Qiagen RNeasy Micro kit and digested by RNase R to obtain circRNA. Reverse transcription PCR amplification and agarose gel electrophoresis analysis were performed to detect target products. Results CircRNA can be detected in all prepared samples. These results showed that the circRNA was widely present in common body fluids of forensic medicine, and had some application value. Conclusion The detection for circRNA can be compatible with the existing DNA detection technology, and its tissue specificity can be used as a new marker for identification of body fluid and has important research value.

Objective Construct a mRNA multiplex amplification system to identify different types of semen stains. Methods First, collect normal, oligozoospermia and azoospermia semen samples to make semen stains. Second, extract total RNA with Qiagen RNeasy Micro Kit. Then use reverse transcript PCR to amplify goal mRNA markers: 2 markers for sperm(PRM1, PRM2), 2 markers for seminal plasma(TGM4, SEMG1) and 2 housekeeping genes(TEF, UCE). Results All semen mRNA markers can be detected in normal semen samples. The RFU of sperm mRNA markers are lower in oligozoospermia semen samples than that in normal controls. No sperm mRNA markers can be detected in the azoospermia semen samples, only seminal plasma specific can be detected. Conclusion The differentiation of normal and azoospermia semen can be achieved by using multiplex mRNA fluorescence amplification system. While normal semen and oligozoospermia semen compared to no statistical difference.