Posted: December 16, 2008 |
Super-resolution microscope technique can resolve cell features down to 20-30 nanometers |
(Nanowerk News) Thanks to a new "super-resolution" fluorescence microscopy technique, Harvard University researchers have succeeded in resolving the features of cells as miniscule as 20-30 nanometers (nm), an order of magnitude smaller than conventional fluorescence light microscopy images, according to a presentation at the American Society for Cell Biology (ASCB) 48th Annual Meeting, Dec. 13-17, 2008, in San Francisco.
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"Super resolution" microscopy techniques enable scientists to visualize cells laterally below 200-300 nm, which is the length scale of most intracellular structures and the level at which the cell gets most of its work done.
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Harvard's "super-resolution" technique, developed by Bo Huang, Xioawei Zhuang and colleagues at the university, is called Stochastic Optical Reconstruction Microscopy (STORM).
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It is one of several higher-resolution fluorescence microscopy techniques that fundamentally surpass the diffraction "blind spot" of conventional light microscopes.
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Because conventional light microscopes cannot resolve two objects closer than half the wavelength of the light, they produce images that appear blurry and overlap no matter how high the magnification.
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According to the Harvard researchers, STORM can record light emitted from a single molecule in the sample.
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Using probe molecules that can be "photoswitched" between a visible and an invisible state, STORM can determine the position of every molecule of interest and can then compile all the molecules' positions to define a structure.
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Huang and colleagues have adapted STORM to study three-dimensional structures and can now visualize a whole cell with an axial resolution of 50-60 nm.
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Multicolor imaging also has been achieved by using photoswitchable fluorophores made of combinatorial pairs of various activator dyes and reporter dyes. Multicolor, 3-D STORM is able to visualize detailed interactions between cell organelles and the cytoskeleton.
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In brain tissue, the researchers used STORM to reveal the fine details in the synaptic structure of the olfactory system.
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The lead author presented, "Seeing the Unseen in a Cell with Super-Resolution Fluorescence Microscopy," on Dec. 16 at the Moscone Center.
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