Human hair shafts are a common source of evidence for mitochondrial DNA (mtDNA) analysis in crime laboratories. There are 100s to 1000s of copies of mtDNA per cell as opposed to the two copies of nuclear DNA found within each cell. This means that it is easier to recover mtDNA in samples with limited nuclear DNA such as hair shafts and old bone, and since there are many copies, individual copies can often have differences in their DNA sequence. This is known as heteroplasmy (heterogeneity in the sequence). We have a new technology that allows us to better detect these sequences. Therefore, this study will perform mtDNA analysis on hairs typically encountered in forensic cases; head and pubic hairs with various levels of chemical and environmental exposure. This will allow us to assess the impact of DNA damage on the findings. Reference samples are physical evidence whose origin is known, such as blood or oral swabs from a suspect, that can be compared to crime-scene evidence. The outcomes of this work will include an increased knowledge of heteroplasmic drift in hairs and the development of models to support the interpretation of heteroplasmy, all of which will help guide and inform the practices being used by the forensic community.
We are recruiting participants who would like to be involved in our project. Each participant will be asked to donate saliva samples by swabbing the inside of their cheek with a cotton swab, blood samples (via a finger stick device), and hair samples 6 hairs from the head and 6 hairs from the pubic region). Due to the current COVID-19 outbreak we will be asking participants to collect samples from themselves to limit person to person interaction. Participants may be asked to donate more than once. All samples will be kept in a locked room. Your DNA profile information may be stored indefinitely in a public, academic database for the purposes of determining frequency estimates for different profiles (EMPOP.org). In addition, the data will be provided to our funding agency (NIJ) as part of the National Archive of Criminal Justice Data (NACJD), which is not a searchable database. At no time will your personal information be directly associated with the profile information. You will be asked to complete and sign a consent form. You may ask any questions you have about the project and the collection process. In addition, you may request to be removed from the study at any point in time. If you are interested in participating in this experiment please contact Shelby Bain at firstname.lastname@example.org.
Participants please click here for videos pertaining to self collection of samples