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13. Eric Rees

Molecular Trajectory Imaging by Eric Rees


Imaging Single Molecule Trajectories and Diffusion.  Each track on this image  is the experimentally-measured trajectory of a single fluorescent  molecule undergoing diffusion on a cell membrane. The paths are colour  coded by their observed diffusivity, from slowest (red) to fastest  (blue).  Method. The small carbocyanine dye molecule DiD was used to  stain the cell membrane of a neuroblastoma cell. The position of these  fluorescent molecules can be precisely tracked by Localisation  Microscopy. The principle of Localisation Microscopy is that the image  of a single molecule is a diffraction limited blur of light  approximately one wavelength (~500 nm) in diameter. The position of  the molecule corresponds to the centre of the blur, and this position  can be determined very precisely, to within 10-20 nm, by computational  fitting. One application of this principle is in super-resolution  imaging, in which we precisely determine fluorophore positions on a  specimen and use this information to draw a similarly precise (i.e.  with sub-wavelength resolution)