Isopycnic centrifugation under low hydrostatic pressure: A novel connecting unit for manual operation of Beaufay's rotor
✍ Scribed by Marco Baggiolini; Ursula Bretz; Max Schneider; Erwin Tellenbach
- Publisher
- Elsevier Science
- Year
- 1977
- Tongue
- English
- Weight
- 527 KB
- Volume
- 77
- Category
- Article
- ISSN
- 0003-2697
No coin nor oath required. For personal study only.
✦ Synopsis
The rotor designed by Beaufay for rapid isopycnic equilibration under low hydrostatic pressure has been modified for manual operation in an MSE ultracentrifuge. A novel, simple connecting unit for loading and unloading the spinning rotor, which comprises a static and a moving part is described. This unit is incorporated into the rotor core and is equipped with a particularly effective V-ring pressure seal. The degree of resolution achieved with the modified assembly is shown to be at least as good as that of the original Beaufay design.
Since its original application to the subcellular analysis of rat liver homogenates, the rotor of Beaufay (l-3) has proved to be an extremely useful tool for isopycnic centrifugation. Its main advantages are the comparatively large sample capacity, very short equilibration times, and the high resolution provided by its ingenious loading and unloading principle. Perhaps most significant is the fact that in Beaufay's rotor the hydrostatic pressure which develops at high speed, and which has been shown to damage subcellular structures (3-6), is much lower than in other rotors. Following the successful separation of rat liver peroxisomes from mitochondria, which led to a biochemical definition of this oxidative organelle (2), Beaufay's rotor has helped to characterize subcellular particles in protozoa (7-9), polymorphonuclear leukocytes (lo-13), and other tissues ( 14), and it has been the crucial device in extensive studies on the heterogeneity of the microsomal fraction of rat liver (15-17).
The rotor was conceived for use in Beckman ultracentrifuges (Beckman Instruments Inc., Palo Alto, Calif.) and is still generally operated in the venerable Model L. We adapted this rotor for use in an MSE ultracentrifuge (Measuring & Scientific Equipment, Crawley, Sussex, England), and we developed a relatively simple loading and unloading system for manual operation, which we now wish to describe because it may contribute to the wider use of the rotor.