The stability and persistence of blood and semen mRNA and miRNA targets for body fluid identification in environmentally challenged and laundered samples

摘要

The identification of body fluids in evidentiary stains may provide investigators with probative information during an investigation. In this study, quantitative reverse transcription polymerase chain reaction (RT-qPCR) assays were performed to detect the presence of mRNA and miRNA in fresh and environmentally challenged samples. Blood, semen, and reference markers were chosen for both mRNA/miRNA testing. Samples of blood and semen were exposed to heat, humidity, and sunlight, and controlled conditions (room temperature, low humidity, and darkness) for 6 months. All mRNA targets were observed through six months under controlled conditions, but were undetected after 30 days in experimental conditions. However, miRNA targets persisted under all test conditions for the duration of the study.