Earlier this week, a group of scientists in Israel shook the world of forensic sciences and questioned the use of DNA testing as the “gold standard”. In a paper published by the Forensic Science International: Genetics journal, researchers showed that it is possible to fabricate DNA evidence. In this paper, the scientists fabricated saliva and blood samples that contained DNA from a person other than the donor of that blood and saliva! Also, the researchers showed that through the use of a DNA database, they could utilize a profile within that database and construct a sample of DNA to match that profile without needing any tissue from that person. In the world of science, this makes a lot of sense, as many people use synthetic DNA oligos in almost every molecular laboratory!
Thankfully, Dr. Frumkin who is the lead author on the paper, has developed a test to distinguish real DNA samples from fake ones using epigenetic modifications, specifically DNA methylation. In the human genome, 70% of the DNA is methylated, meaning that it contains methyl group modifications in a CpG dinucleotide context. Methylation at the promoter region is associated with gene silencing. Synthetic DNA, however, would lack this specific epigenetic modification, and therefore can be distinguished from the real deal.
As our world becomes increasingly reliant on scientific technologies, the idea that DNA can be planted at a crime scene is very scary. Hopefully with tests like the one generated by Dr. Frumkin will be common practice to ensure that science stays ahead of the game.
By Alisha Jamal, University of Toronto