Effects of microwave radiation on the digestion of proteins involved in body fluid identification

Abstract

Body fluid identification plays an important role in understanding how the events during a crime may have taken place. The presence of a body fluid may help identify an individual who committed a crime, while the type of body fluid present may help investigators determine how a crime occurred. Current body fluid identification techniques are not always conclusive and may only suggest the presence of a body fluid type. A protocol developed by the New York City Office of the Chief Medical Examiner (OCME) established a method that confirms body fluid type through mass spectrometry. To identify marker proteins in a body fluid sample, the proteins in the sample must be digested into their smaller peptide fragments. Currently, this digestion is performed with trypsin in an overnight process that takes at least eight hours to complete. Microwave radiation has been shown to assist in the digestion of the body fluid protein samples, and the time needed for digestion reduced from eight hours to just minutes. The effects of microwave radiation on the digestion of protein samples commonly found in body fluids were examined here and compared to traditional methods. Ideal microwave assisted temperature of protein samples was determined to be 37°C, however no significant differences were observed between microwave assisted digestion and the traditional methods of digestion at different incubation times. Overall, this research shows microwave radiation can be used to assist protein digestion, achieving similar results to traditional digestion methods at 37°C