Evaluation of Nuclear DNA from Rootless Hair for Forensic Purposes

Rootless hair is widely regarded as a poor source for DNA-based forensics. However, rootless hair shafts are known to contain preserved DNA that can be recovered and analyzed even after thousands of years. We have developed technology for exploiting the DNA found in rootless hair for forensic applications.

We will present a description of the characteristics of DNA found in rootless hair shafts. These characteristics include small fragment lengths that preclude its use in many PCR-based assays. We will describe the biological process that gives rise to these DNA fragments and describe the technology that we developed to efficiently convert these DNA fragments for direct sequencing.

We will also present a computational pipeline that converts this direct DNA sequence data into high-quality genotype files of the type available from direct-to-consumer genetic testing companies. These genotype files are suitable, then, for forensic genetic genealogy. This approach has helped solve some of the oldest and most difficult high-profile violent crime cases.

Finally, synthesizing observations from an exploration of hair types from many individuals, we will provide an outlook for the future of this technology, including existing technical and ethical hurdles to wide adoption.