Even though I did much of my PhD thesis with the characteristic whining of two ancient, wardrobe-sized Beckman model E analytical ultracentrifuges in the background, I didn't really expect to get a chance to write something about this technique any time soon. It was widely used to study molecular weight and assembly of proteins back in the 1970s but for a time it became so unfashionable that there was no company left making or servicing the instruments, and only hardcore fans like my PhD supervisor, Rainer Jaenicke, kept the last of these dinosaurs alive.
By now, the technique has been rediscovered, new centrifuges have been developed and built, and various groups are using the technique. In an intriguing development, the groups of Steve Harding and Thomas Heinze have shown that certain carbohydrates can assemble reversibly just like oligomeric proteins. Read all about it in my news story which is out now in Chemistry World online, free access:
Searching for an illustration for this article, I discovered this video of a simulation showing what happens to protein molecules in the cell of an ultracentrifuge. Simulation is of lysozyme in water, so nothing to do with carbohydrates, but I thought it's a lovely visualisation of the technique:
Source: Díez A, Ortega A, Garcia de la Tore J (2011). "Brownian dynamics simulation of analytical ultracentrifugation experiments". BMC Biophysics. DOI:10.1186/2046-1682-4-6.
via wikimedia commons.