Name: single-molecule imaging of nuclear transport
Uploaded: 2010-06-09T17:00:00
Description: Watch this Scientific Journal Video about Single-Molecule Imaging of Nuclear Transport at JoVE.com

This project was supported by the Research Capacity Enhancement Grant (Bowling Green State University).

1. Preparation of the cell system for single molecule experiment
<ol>
<li>At least one week in advance, start a fresh culture of HeLa cell line from a stock by thawing at 37&deg;C and putting in a 25 cm2 culture flask with 5 mL media, Incubate the cells at 37&deg;C within 5% CO2 incubator for 24 hours and split it at least 3 times in order to provide an optimal condition for the cells. However the cells should not be split more than 20 times due to proclivity of their growth rate to slow down si...

<ol>
	<li>Ma, J., Yang, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Single+Molecule+Snapshots+of+Three-Dimensional+Distribution+of+Transient+Interactions+in+Nuclear+Pore+Complex.">Single Molecule Snapshots of Three-Dimensional Distribution of Transient Interactions in Nuclear Pore Complex.</a> Proc. Natl. Acad. Sci. USA. , (2010).</li><li>Sarma, A., Goryaynov, A., Yang, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Single+Molecule+Imaging+of+the+Calcium-Regulated+Nuclear+Pore+Permeability.">Single Molecule Imaging of the Calcium-Regulated Nuclear Pore Permeability.</a> , .</li><li>Yang, W., Musser, M. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Visualizing+single+molecules+transiting+through+nuclear+pore+complexes+using+narrow-field+epifluorescence+microscopy.">Visualizing single molecules transiting through nuclear pore complexes using narrow-field epifluorescence microscopy.</a> Methods. 39, 316-328 (2006).</li><li>Yang, W., Gelles, J., Musser, M. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Imaging+of+single-molecule+translocation+through+nuclear+pore+complexes.">Imaging of single-molecule translocation through nuclear pore complexes.</a> Proc. Natl. Acad. Sci. USA. 101, 12887-12892 (2004).</li></ol>

Care must be taken to insure a proper colocalization of NE and single molecules during the experiment. It is also important to provide a high signal noise ratio, especially when the signal is low due to poor labeling or photobleaching. Localization precision is limited by background noise (arising from out-of-focus fluorescence, CCD readout noise, dark current and other factors).

single-molecule imaging of nuclear transport

The utility of single molecule fluorescence microscopy approaches has been proven to be of a great avail in understanding biological reactions over the last decade. The investigation of molecular interactions with high temporal and spatial resolutions deep within cells has remained challenging due to the inherently weak signals arising from individual molecules. Recent works by Yang et al. demonstrated that narrow-field epifluorescence microscopy allows visualization of nucleocytoplasmic transport at the single molecule level. By the single molecule approach, important kinetics, such as nuclear transport time and efficiency, for signal-dependent and independent cargo molecules have been obtained. Here we described a protocol for the methodological approach with an improved spatiotemporal resolution of 0.4 ms and 12 nm. The improved resolution enabled us to capture transient active transport and passive diffusion events through the nuclear pore complexes (NPC) in semi-intact cells. We expect this method to be used in elucidating other binding and trafficking events within cells.

Watch this Scientific Journal Video about Single-Molecule Imaging of Nuclear Transport at JoVE.com

Single-Molecule Imaging of Nuclear Transport

Single molecule microscopy approch provided novel insights into nuclear transport.

The utility of single molecule fluorescence microscopy approaches has been proven to be of a great avail in understanding biological reactions over the ...

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