Research Scientist • 2001-2002 • Sandia National Laboratories, Livermore, CA
The Han group applies advanced microfluidics and nanofluidics to develop new tools and technologies for biomolecule separation and analysis.
Understanding complicated network dynamics requires the ability to experimentally monitor enzymatic activities within cells. All currently available techniques, however, take measurements by averaging over many cells, which may or may not be at the same stages of intracellular signal processing. Because such population-average measurements may not accurately describe the inner workings of complex pathways, there is a need for new techniques that can measure enzymatic activities at the single-cell level.
We have developed a novel nanofluidic biomolecule concentration device which can be used to collect and trap proteins contained in a given sample into a much smaller volume, thereby increasing the local concentration significantly. In collaboration with the Lauffenberger / Griffith lab, we used the device to perform concentration-enhanced cell kinase activity assays with lysates from a singlecell. Our device increased reaction velocity, enhanced sensitivity, shortened the assay time, and decreased the amount of sample needed. We are continuing to optimize this simple and efficient device in order to create a generic and powerful tool for diagnostics and systems biology research.