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Nanoscale Analysis Labs
FiReaNGeL writes "Imagine being able to rapidly identify tiny biological molecules such as DNA and toxins using less than a drop of salt water in a system that can fit on a microchip. It's closer than you might believe: in a paper appearing next week in PNAS, a team of researchers proves for the first time that a single nanometer-scale pore in a thin membrane can be used to accurately detect and sort different-sized polymer chains (a model for biomolecules) that pass through or block the channel. This could lead to rapid detection systems for pathogens and toxic chemicals."
As the NIST press release blurb correctly indicates, mass spectrometry can be powerful for sorting and identifying biomolecules. DNA is probably the simplest example, because enzymes can chop a long strand of DNA into many small pieces. These enzymes cut only in places with well-defined sequences, so with enough information about the length of the resulting pieces the whole sequence can be reconstructed. How practical is that? Well, the method used in the various genome projects is conceptually very similar, so looking at a bunch of fragments of biomolecules can be a practical way to identify them.
The pores add a capability of doing the measurements on very small samples, e.g., DNA from a few cells, while keeping the setup small. The pores can also be effectively multiplexed, at least in principle.
Other clever uses of mass-spectrometry are possible, essentially because molecular biology offers many tools that are supposed to produce a predictable distribution of fragments. Indeed, it is always a trade off between the number of different fragments and the sharpness of their mass distributions, but specific experimental signatures sometimes can be obtained. For example, with proper design one can arrange for a certain size fragment to appear after several cutting steps only if a given DNA or protein sequence has mutated or is from a known pathogen.