Carbon nanotubes illuminate high-resolution sub-cellular microscopy

alpert-photo3Of potential interest to QSTORMers, an international team recorded motor protein movement in live cultured cells with millisecond time resolution and 20-50 nm spatial resolution by tagging them with fluorescent single-walled carbon nanotubes (SWNTS) and applying a single-molecule tracking algorithm to images from a confocal microscope equipped with a spinning-disk head.  Because the SWNTS fluoresce in the near-infrared range, they are easily distinguishable from normal background fluorescence, which rarely inhabits the near-infrared portion of the spectrum in biological tissues.  The SWNTS, which are bound in short DNA oligonucleotides and attached to kinesin with HaloTags, are bright, non-blinking, and highly photostable. The team introduced about 100 per cell, and was able to track them individually for 90 minutes.  The report, “High-resolution mapping of intracellular fluctuations using carbon nanotubes,” by Nikta Fakhri, et al., appears in the May 30 edition of Science (v.344, p. 1031), and the supplemental materials include brief videos.  The SWNT tags were introduced to the cells using “nucleofection,” a procedure invented by the biotechnology company Amaxa.   While the team refers to this technique as “non-invasive,” it’s difficult to assess how it might impact normal protein transport along microtubules.

This entry was posted in Alpert Lab Notes, Team Blog. Bookmark the permalink.