microRNA Detection in Blood, Urine, Semen, and Saliva Stains After Compromising Treatments

Abstract Evaluation of micro RNA (mi RNA ) expression as a potential method for forensic body fluid identification has been the subject of investigation over the past several years. Because of their size and encapsulation within proteins and lipids, mi RNA s are inherently less susceptible to degradation than other RNA s. In this work, blood, urine, semen, and saliva were exposed to environmental and chemical conditions mimicking sample compromise at the crime scene. For many treated samples, including 100% of blood samples, mi RNA s remained detectable, comparable to the untreated control. Sample degradation varied by body fluid and treatment, with blood remarkably resistant, while semen and saliva are more susceptible to environmental insult. Body fluid identification using relative mi RNA expression of blood and semen of the exposed samples was 100% and 94%, respectively. Given the overall robust results herein, the case is strengthened for the use of mi RNA s as a molecular method for body fluid identification.