Battelle’s Breakthrough STR Genotyping Allows Law Enforcement to Identify Criminals in Minutes or Hours Using DNA Samples

As national security threats evolve, so must scientific and diagnostic approaches to human DNA identification and characterizations. Both the intelligence community (IC) and law enforcement agencies seek new forensic, field solutions that allow them to identify threat actors – like terrorists and criminals – faster, more accurately, and more cost-effectively, improving our national security posture.

Next-generation genome sequencing is gaining traction in law enforcement for human identification; however, the challenge is genotyping short-tandem repeat (STR) loci using current genome sequencing technology. Although STRs are the most commonly used forensic markers for identity analysis, STR analysis conducted on high-throughput sequencing platforms has proven difficult in the field and in a timely manner.

Our highly skilled scientists devoted hundreds of hours to research, testing, and evaluating genome sequencing methods and platforms to accelerate human (and even microbial) identification. Our unique approach allows us to genotype STR loci on next-generation, high-throughput sequencing technology platforms, like Illumina.

Utilizing a modified reference genome for analysis of sequencing reads, we were able to determine the STR genotype of all 13 core STR loci used by the Federal Bureau of Investigation (FBI). Essentially, our next-generation STR genotyping solution occurred in two stages: (1) We designed custom PCR primers that amplified STR loci, so that scientists could focus on the precise portion of the human genome that they wanted to genotype. (2) We took the sequencing reads and processed them through our custom bioinformatics pipelines for rapid and accurate genotyping.

Not only were we the first to publish our success in genotyping STR loci, we were the first to genotype STRs on the Illumina Short-Read Frequency sequencer – the most complex and most commonly used platform in the scientific community. We also demonstrated that we could genotype STR loci and extract sequencer data in minutes or hours – not days or weeks – with modest computing power, which is ideal for field applications.

In addition to human genotyping applications for law enforcement, we learned that we could apply the same bioinformatics approaches to microbial genotyping for medical and diagnostic applications.