Exploration of RNA Degradation in Dried Body Fluid Stains as a Means of Estimating the Age of the Samples, Oklahoma, 2018-2019

The overall goal of this project was to understand the degradation characteristics of mRNA molecules in dried body fluid stains such that the relationship between degradation and the passage of time could be explored and used to develop a forensic tool to estimate the age of the stain (i.e., determine the time since deposition, TsD). Research has demonstrated that RNA degradation correlates with the passage of time in dried stains and have defined degradation kinetics for multiple mRNA transcripts present in dried blood, semen, and saliva stains. The current study collected detailed degradation kinetics for multiple transcripts in stains stored in real world environments with varying conditions of temperature, relative humidity, and sunlight exposure. Results suggest it may be possible to model degradation kinetics mathematically and develop an algorithm useful for estimating TsD in biological evidence recovered from crime scenes.