Harvard’s Wyss Institute researchers are bringing a specific and multiplexed genetic diagnostic technology to market with NuProbe Global, a Boston based company. It addresses the current need to detect rare genetic mutations, which may be present in only a few cells of the body. Current detection techniques using gene amplification are not specific enough and return false positives, and also lack multiplexing capabilities to detect multiple mutations in a single tube. NuProbe Global’s technology increased the sensitivity of single point mutations by 100 fold when applied with conventional qPCR and next-generation sequencing methods, and was shown to detect hundreds of sequences and mutations in a single test. This assay would enable rapid and simple gene testing for patients.
The technology by Professor Peng Yin and postdoctoral fellow David Yu Zhang detects rare mutations in DNA or RNA by using complementary detection probes, which are partially protected by a shorter complementary strand. An uncovered section of DNA on the probe hangs off the end, and is called a “toehold”. When this probe comes in contact with the actual genetic sequence of interest, it binds it fully including the toehold segment, and pushes the shorter protection strand off through thermodynamic competition (the probe binds more strongly to the genetic sequence of interest than the protection strand). The protection strand prevents other nontarget sequences from binding to the probe, increasing the specificity of the binding.
NuProbe is a joint venture between the USA and China. It announced that it raised $11 million in Series A funding this week to expand its team for clinical trials and commercialization. It has been validated in cancer patient blood samples and is undergoing preliminary clinical trials.
More on toehold DNA technology: Programming biomolecular self-assembly pathways…; Control of DNA Strand Displacement Kinetics Using Toehold Exchange…; Toehold Patent…