Articles by En Cai in JoVE
Fluorescensimagografi med One-nanometer Nøjagtighed (FIONA) Yong Wang*1,2, En Cai*1,2, Janet Sheung1,2, Sang Hak Lee1,2, Kai Wen Teng2,3, Paul R. Selvin1,2,3 1Department of Physics, University of Illinois at Urbana-Champaign, 2Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, 3Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign Enkelte fluoroforer kan lokaliseres med nanometer præcision ved hjælp af FIONA. Her er en sammenfatning af FIONA teknik er rapporteret, og hvordan man udfører FIONA eksperimenter beskrives.
Other articles by En Cai on PubMed
Using Fixed Fiduciary Markers for Stage Drift Correction Optics Express. May, 2012 | Pubmed ID: 22714205 To measure nanometric features with super-resolution requires that the stage, which holds the sample, be stable to nanometric precision. Herein we introduce a new method that uses conventional equipment, is low cost, and does not require intensive computation. Fiduciary markers of approximately 1 µm x 1 µm x 1 µm in x, y, and z dimensions are placed at regular intervals on the coverslip. These fiduciary markers are easy to put down, are completely stationary with respect to the coverslip, are bio-compatible, and do not interfere with fluorescence or intensity measurements. As the coverslip undergoes drift (or is purposely moved), the x-y center of the fiduciary markers can be readily tracked to 1 nanometer using a Gaussian fit. By focusing the light slightly out-of-focus, the z-axis can also be tracked to < 5 nm for dry samples and
3D Super-Resolution Imaging with Blinking Quantum Dots Nano Letters. Nov, 2013 | Pubmed ID: 24093439 Quantum dots are promising candidates for single molecule imaging due to their exceptional photophysical properties, including their intense brightness and resistance to photobleaching. They are also notorious for their blinking. Here we report a novel way to take advantage of quantum dot blinking to develop an imaging technique in three-dimensions with nanometric resolution. We first applied this method to simulated images of quantum dots and then to quantum dots immobilized on microspheres. We achieved imaging resolutions (fwhm) of 8-17 nm in the x-y plane and 58 nm (on coverslip) or 81 nm (deep in solution) in the z-direction, approximately 3-7 times better than what has been achieved previously with quantum dots. This approach was applied to resolve the 3D distribution of epidermal growth factor receptor (EGFR) molecules at, and inside of, the plasma membrane of resting basal breast cancer cells.