New ‘Barcode’ System Puts DNA Sample to the Authenticity Test
Engineers from Duke University and NYU’s Tandon School of Engineering have demonstrated a method of adding a sample of artificially created genetic material to evidence, which will allow lab workers to match the samples processed in the lab. “If you think about conventional encryption techniques, like security for a smartphone, there’s usually a passcode that only one person knows, “said Mohamed Ibrahim, a system-on-chip designer at Intel Corp. and a Ph.D. graduate of Duke. “Our idea is to inject non-harmful material into genetic samples immediately when they are collected in the field that act as a similar password. This would ensure that the samples are authentic when they reach the processing stage.”
Most genetic identification is done using polymerase chain reaction (“PCR”), a technique for sequencing a few short sections of human DNA, which can be used to accurately identify the person who left biological material at the scene of a crime. The FBI has identified 13 sites on the human genome which, when compared amongst many samples, ensures that each sample will provide reliable identification of its source. This method is far cheaper than sequencing a person’s entire genome, which still runs about $1,000 per sample. And as PCR systems become more widespread, manufacturers are developing new ones that are smaller and cheaper.
Ibrahim, and his colleagues Krishnendu Chakrabarty, Tung-Che Liang, Ramesh Karri, and Kristin Scott, developed the system to address the growing presence of cyberbiosecurity threats by developing a unique “bar code” made of DNA pairs that, when read through a PCR device, can identify from where the source was collected.
For instance, a forensic team can have unique “bar coded” genetic material that is added to crime scene evidence, which is “scanned and verified” in the lab to ensure the right sample is being processed. “When the right primers are used to unlock a barcode, you should get a positive result,” said Ibrahim. “If you don’t, then that means that the sample is not genuine. Some sort of switching or alteration has occurred.”
This new system, if widely adopted by forensic investigators, will not address the host of other processing errors that have plagued forensics labs across the country, as those problems are the result of human carelessness or worse. But removing the chance for this kind of human error is a much-needed positive step.