In a May paper in Nature Biotechnology, Ludwig Johns Hopkins researchers Joshua Cohen, Bert Vogelstein, Kenneth Kinzler and Nickolas Papadopoulos reported an improved next-generation DNA sequencing technology named SaferSeqS (for “Safer Sequencing System”). Such technologies are critical to liquid biopsies, which detect cancer by analyzing DNA fragments shed by tumors into body fluids. SaferSeqS, they show, is a major improvement over widely used methods adapted from one developed at Ludwig Johns Hopkins a decade ago named Safe Sequencing System. It improves the sensitivity and reduces the baseline error rate of mutation detection more than 100-fold in comparison to other methods. SaferSeqS involves tagging both strands of each isolated DNA fragment with a unique DNA sequence equivalent to a barcode and employing duplex sequencing, which relies on the structural redundancy of DNA to distinguish real mutations from errors: If both strands of a DNA molecule have corresponding mutations at the same spot, it is more likely to be authentic than an experimental artifact. The researchers compared their analysis of samples to previous results from the CancerSEEK test, a liquid biopsy for eight common cancers that was developed at Ludwig Johns Hopkins. SaferSeqS significantly improved sensitivity, detecting mutations not previously captured in 68% of the samples tested.
This article appeared in the August 2021 issue of Ludwig Link. Click here to download a PDF (2MB).