Abstract: Objective To establish an on-site biological body-fluids identification method in saliva samples based on Recombinase Polymerase Amplification（RPA） technology. Methods Using DNA-RNA co-extraction technology, the total RNA of the sample was reverse-transcribed into cDNA. RPA primers were designed for the saliva-specific gene marker HTN3 to construct a HTN3 RPA detection method, and the specificity and application effect of the method were tested. Results The reverse transcription product can be reacted at 39℃ for 20 min to complete the effective amplification of the target fragment. The amplified band was completely consistent with the target sequence. This method has obtained stable and reliable results by testing of 20 on-site biological body-fluids materials. Conclusion This study established a reverse transcription RPA method for the detection of salivary spots. It has strong specificity, and will greatly shorten the amplification time. The results were stable and easy to be determined, which is suitable for rapid laboratory testing. The STR typing of biological evidence can be completed simultaneously. The method provides a new strategy for forensic body fluid identification.

Key words: forensic evidence, recombinase polymerase amplification, saliva, body fluid identification

摘要： 目的 建立一种基于重组酶聚合酶扩增（RPA）技术的现场唾液生物属性鉴定方法。方法 利用DNA-RNA共提取技术，将样本总RNA反转录成cDNA，针对唾液特异性分子标识HTN3设计RPA引物，构建HTN3 RPA检测方法，并测试该方法的特异性和应用效果。结果 反转录产物在39 ℃恒温反应20 min即可完成目的片段的有效扩增。扩增条带与目的序列完全一致。在对20份现场检材的检验中该方法均获得了稳定可靠的检测结果。结论 建立的反转录RPA检测唾液生物属性方法特异性强，极大缩短了扩增时间，结果稳定且易于判定，适合实验室快速检测。该方法可同步完成物证的STR分型检验，为丰富法医物证体液鉴定提供了一种新的策略和方法。

关键词: 法医物证学, 重组酶聚合酶扩增, 唾液, 体液鉴定