\u201cYou can see the cell for maybe a few hours maximum before the fluorescent light dies out, but it takes several days to conduct a stem cell experiment,\u201d said Zhuo. \u201cScientists commonly use fluorescent tagging because there\u2019s no better way to monitor live cells due to their low imaging contrast among cellular organelles. That urges us to develop a label-free and high-resolution imaging method for live cell study.\u201d<\/p>\n
The Illinois team\u2019s microscope functions with an LED light source and a photonic crystal biosensor made from inexpensive materials like titanium dioxide and plastic using a fabrication method like nanoreplica molding.<\/p>\n
\u201cOur sensor can be massively fabricated easily, and our cost to make the sensor is less than $1 each.\u201d noted Zhuo.<\/p>\n
In Zhuo\u2019s apparatus, the photonic crystal biosensor is an optical sensor which can apply to any attachable cells. The sensor surface is coated with extracellular matrix materials to facilitate cellular interactions, which are then viewed through a normal objective lens and recorded with a CCD camera.<\/p>\n
\u201cThe advantage of our PCEM system is you can see as the [live] cell is beginning to attach to our sensor, and we can quantitatively and dynamically measure what happened at that time,\u201d Zhuo said. \u201cWe\u2019re able to actually measure a very thin layer on the bottom of the cell that\u2019s about 100 nanometers, which is beyond the diffraction limit for visible light.\u201d<\/p>\n
In the future, Zhuo plans to outfit the microscope with higher imaging resolution and someday hopes to be able to build a library of cell adhesion data for scientists.<\/p>\n
\u201cDifferent types of cells will have different dynamic attachment profiles.\u201d she explained. \u201cWe can use this library to screen different types of cells for tissue regeneration, disease diagnostic, or drug treatment, for example, see how diseased cells spread, or see how the cancer cells respond to different drug treatment.\u201d<\/p>\n
Cunningham is the Donald Biggar Willett Professor of Engineering and director of the Micro + Nanotechnology Lab at Illinois. This project was funded by grants from the National Science Foundation and National Institutes of Health. Research collaborators include associate professor Brendan Harley and post-doctoral researcher Ji Sun Choi (chemical and biomolecular engineering), and graduate student Hojeong Yu (electrical computer engineering).<\/p>\n
Contact: Brian Cunningham, Micro + Nanotechnology Lab, University of Illinois at Urbana-Champaign, 217\/265-6291; bcunning@illinois.edu.<\/p>\n
Yue Zhuo, Beckman Institute, University of Illinois at Urbana-Champaign,yuezhuo2@illinois.edu.<\/p>\n
Writer: Laura Schmitt, Micro + Nanotechnology Lab, University of Illinois at Urbana-Champaign , 217\/244-6292, lschmitt@illinois.edu.<\/p>\n<\/div>\n