DNA-analysis is a powerful forensic tool to link a questioned individual to a biological stain detected at a crime scene because of its high discriminating power. However, a DNA profile can only provide information about the potential identity of the donor; it does not provide information on how or when it was deposited. Consequently, in many cases, additional information is necessary to link a DNA profile to a criminal act.
Information about the presence of body fluids e.g. blood or saliva, can give additional indications regarding the activity required for its deposition. Most forensic laboratories still use the classical presumptive tests for body fluid prediction. These are simple and fast to perform, but their accuracy is poor and can give false results. Due to these shortcomings, several new alternative tests have been proposed. Most promising are the new tests measuring gene expression from mRNA markers. To be able to identify which body fluid is present in the sample will have a great impact as evidence in court, as it may rule out innocent contact from transfer of skin cells. In addition it can function as an investigate tool for the police.
The project
The goal of the project is to optimize and extend the currently used multiplex-PCR for mRNA analysis by identifying and testing new markers for detection of body fluids of interest. The practical work in this project will be performed at the Section for Forensic Biology at Rikshospitalet.
The work will consist of literature searches, primer design, molecular lab and statistical analysis. Methods that will be used are co-extraction of RNA and DNA, reverse transcription of mRNA, multiplex PCR of cDNA and capillary electrophoresis for fragment separation.
Supervisor: Ane Elida Fonneløp