Colloquium – John Kasianowicz (NIST, USF, Columbia)
Measuring Molecules at the Single Molecule Limit: Sequencing DNA, Sizing Polymers, Identifying Proteins (& More) with Nanometer-Scale Pores
Biological nanometer-scale protein pores are the basis of nerve and muscle activity. With the goal of providing low-cost measurements for health care applications, we have been adapting several types of nanopores for the detection, characterization, and identification of molecules. For example, when a single molecule enters a pore, its physical and chemical properties control both the degree by which it reduces the ionic current (that otherwise flows freely) and its dwell time there. Thus far, our work led to two novel DNA sequencing methods, the ability to discriminate between individual polymers based on their size, the means to quantitate protein concentration, and a technique for identifying subtly different species of metallo-nanoparticles. In addition, we demonstrated that a nanopore can also be used to identify proteins. This new method could markedly improve healthcare diagnostics and allow more blood analyses to be performed at point-of-care facilities. We are also investigating the possible use of nanopores as the read head in molecular-based memory storage devices and the role of ion channels in the competition between bacteria. This ongoing work is a collaborative effort with groups at Columbia University (Jingyue Ju), CY Cergy Paris Université (Abdelghani Oukhaled), Freiburg University (Jan Behrends), and the DoD (Sina Bavari, Rekha Panchal, Captain Rick Gussio, and Colonel Kelly Halverson).