Semen stain identification is one of the crucial tasks for collection of criminal evidence by forensic techniques. Substances such as DNA and RNA contained in semen stains can serve as a source of personalized evidence targeting the suspect. Therefore, semen stain identification is vital to inferring the case attributes and the facts of the crime. The conventional methods of forensic stain identification focus on the detection of specific-function protein and/or high-content protein, such as alkaline phosphatase and PSA. Although the specificity of such protein markers is relatively high, these methods yield a limited rate of success for several factors, including poor stability, low sensitivity of the target protein, and possible subjectivity of the performer. In order to overcome these limitations, new technologies such as Raman spectroscopy, mass spectrometry for protein markers, sperm-specific aptamer, mRNA, microRNA, and DNA methylation assays have been studied and recommended by many investigators. These new technologies are paving a new ground for personalized trace analysis and even for detection of over-timed specimens.
斑痕类型鉴别是法医物证检验的重要步骤之一，精斑中所含有的DNA和RNA的鉴定可以提供识别犯罪嫌疑人的个性证据，因此精斑的确认对案件属性和犯罪事实具有至关重要的作用。精斑识别的传统方法注重检测其中特异性的功能蛋白或者含量高的蛋白，如碱性磷酸酶、前列腺特异性抗原等。尽管这些标志物特异性相对较强，但蛋白质稳定性差，灵敏度低，检测结果易带主观性倾向等,限制了传统方法的检出率。为了克服这些限制，拉曼光谱法、质谱检测蛋白标志物、精子适体技术、特异性mRNA和microRNA的检测、组织差异DNA甲基化等新技术相继出现，这些方法为微量、甚至陈旧性等疑难检材的个性鉴定开辟了新的途径。.
Keywords: DNA methylation; aptamer; mass spectrometry; protein marker; semen stain identification.