Effect of Time on Detection of microRNAs and Prostate Specific Antigen in Suspected Dried Stains in Sexual Assault Crimes

Abstract

Forensic body fluids represent an important support to professionals when detected, collected and correctly identified. Since sexual violence crimes are usually unwitnessed crime, evidence of semen can play a crucial role in corroborating the victim’s allegations during the initial phase of the investigations. Through many years, various serology- based methodologies; chemical tests, immunological tests, protein catalytic activity tests, spectroscopic methods, and microscopy, were used for body fluid identification but they were prone to various limitations such as sample consumption, intensive labor, time consumption as well as varying degrees of sensitivity and specificity. Recent advances in forensic genetics have led to the development of several messenger RNA (mRNA) markers that are expressed in a tissue-specific manner, and their expression patterns can confirm specific body fluids even after long periods of time under controlled conditions. However; humidity, heat, UV light, and ubiquitous ribonucleases are detrimental to mRNA stability as a specific and sensitive biomarker for forensic applications which became difficult to set aside. Micro-RNA is a small non-coding, single stranded RNA. It is characterized by small size (about 20-25 bases in length), which makes it stable and less prone to degradation by chemical and/or physical environmental strains than mRNA. Due to tissue –specific expression pattern of mi RNA, several mi RNA have been investigated as potential biomarkers of body fluids.