Tonight, I watched a 2019 London Calling session by Katie Doroschak from the University of Washington on “Molecular tagging with nanopore-orthogonal DNA strands.” Molecular tagging systems use DNA to identify physical objects. Doroschak shared examples of secret exchange and counterfeit pharmaceutical detection. The research team used the MinION and created digital tags and codewords with DNA. The molecular bit sequence is a modular combination of a unique sequence of a specific length. The unique identifiable region actually helps avoid base calling, explained Doroschak. The tags were designed in two sizes. They created molecular bits to have distinct nanopore squiggles. In the end, they just needed 3-5 minutes of sequencing! They created shelf-stable tags that are shelf-stable and can be rehydrated for sequencing. What a clever system!
