制备不同时间的血痕样品,采用实时定量PCR检测不同时间点18SrRNA和ACTB mRNA含量,并进行统计学分析。结果发现在10周内,随血痕经过时间延长,18SrRNA基因片段和ACTBmRNA基因片段发生了较明显降解,具有一定的时间规律性。18SrRNA基因片段较ACTB mRNA降解速度快。采用实时定量PCR技术检测18SrRNA和ACTBmRNA含量变化,为推断血痕经过时间提供了新的方法和客观依据。 Blood samples were prepared at different times. Real-time quantitative PCR was used to detect 18SrRNA and ACTB mRNA levels at different time points, and statistical analysis was performed. The results showed that within 10 weeks, with the passage of time after bloodstains, 18SrRNA gene fragments and ACTBmRNA gene fragments occurred more obvious degradation, with a certain time regularity. 18SrRNA gene fragment degraded faster than ACTB mRNA. Real-time quantitative PCR detection of 18SrRNA and ACTBmRNA content changes, to provide a new method and objective basis for inferring the passage of bloodstain.