Laser Scattering of Mitochondria

Laser scattering of mitochondria, the "power plants" of cells, can immediately identify early-stage liver cancer cells and potentially monitor stem cells as they undergo various stages of development. At the APS March Meeting, Paul Gourley of Sandia (plgourl@sandia.gov) reported the latest uses of the "biocavity laser," an aluminum-gallium-arsenide based design that continuously pumps in single human cells into a chamber for analysis. The laser's beams are altered in their passage through the cells. The 800-nanometer light in the experiments is not absorbed by most of the cell, except by its hundreds of mitochondria, which are responsible for scattering 90-95 percent of the light.

By analyzing the scattering patterns, the researchers determined the distribution of mitochondria in the cell, and could instantly determine whether the cell was healthy (in which case the mitochondria cluster cooperatively around the cell nucleus) or cancerous (in which case they are apathetically sprawled across the cell). The process is highly accurate, works much more quickly than traditional techniques, and does not require the usual pre-treatment of cells with chemical reagents or fluorescent molecules.

Co-author Bob Naviaux of UC-San Diego added the biocavity laser technique also has the potential to rapidly identify the in-between states of stem cells as they transform into their final identities. (Also see Sandia News release at http://www.sandia.gov/news-center)