阐明遗留于犯罪现场的人类体液斑痕的组织来源对明确案件性质极为重要。传统的体液鉴定方法，包括血清学和免疫学方法，不适用于法医微量和降解检材。平均长度仅22个核苷酸的microRNAs具有独特优势，更适宜用于法医降解检材分析；其组织差异性表达特征为体液斑的组织来源鉴定带来了希望。然而目前筛选不同体液中差异表达的microRNAs的检测技术存在效能不足的问题，体液标记microRNAs数量有限，尚不能够有效地鉴别法医学常见体液。新一代测序技术，为体液标记microRNAs的法医学研究提供了新的前景。本课题拟在前期工作的基础上，利用新一代测序技术高通量并行测序的特点，在全基因组范围内以单碱基分辨率检测和量化人类不同体液中microRNAs的表达情况，探索和寻找具有法医学鉴定意义的microRNAs，为进行不同体液斑鉴定奠定理论基础和提供科学依据。

Identifying the origin of body fluids left at a crime scene is significant to uncover the criminal nature of an event. Conventional serology- and immunology- based methods for body fluid identification are prone to various limitations, they are not suitable for the analysis of degraded and trace samples. The intrinsically short fragment (approximately 22 nt) and tissue-specific expression pattern enable microRNA as an ideal biomarker for body fluid identification. However, current technologies for screening differentially expressed microRNAs are obviously insufficient, and the number of microRNA markers is not enough for identification of forensically relevant body fluids. Next-generation sequencing technology highlights the study of body fluid specific microRNAs in forensic medicine. Based on the previous work experience, we intend to clarify the genome-wide expression patterns of microRNAs in human body fluids at nucleotide resolution using the Next-generation sequencing, which could provide theoretical basis and scientific evidence of the potential use for body fluid identification.