Identification of body fluids—menstrual blood, saliva, and nasal secretions—over different periods of time, using mRNA

Abstract

Background: Forensic examination of biological samples started at the beginning of the twentieth century by applying the ABO blood group system in evidence related to crimes or human identification. In the present study, real-time PCR multiplex was used to identify dried and stored swabs (saliva, nasal secretions, and menstrual blood) through the target genes of saliva (histatin 3 and statherin), nasal secretions (statherin and BPIFA1), and menstrual blood (metalloproteinases 10 and 7). Results: The expressions of histatin 3 and statherin in the dried saliva decreased over days of storage with a significant p value of <0.001. BPIFA1 was highly expressed in nasal secretions, and the expression level significantly decreased throughout the study with a significant p value of <0.001. The MMP7 and MMP10 genes were highly expressed in the menstrual blood, and the expression level decreased over days of storage with a significant p value of p<0.001. Conclusions: Dried swabs of the saliva, Nasal secretions, Menstrual blood can be identified over the storage duration of the study using mRNA profiling of specific markers.