Density Gradient Separations in Vertical Tube, Near Vertical Tube, Fixed Angle, and Swinging Bucket Rotors: A Comparative Study

摘要

Over the years, researchers have used density gradienttechniques for separating viruses and macromolecularspecies such as proteins, subcellular organelles, andnucleic acids. Brakke first used these techniques, anda publication by Griffith provides a thorough discussion of the rate zonal and isopycnic density gradient procedures. Both fixed angle and swinging bucketrotors have been used for these two methods. Thevertical tube rotors with the tube angle fixed parallelto the axis of rotation are also being used for densitygradient studies in the ultracentrifuge. This paper compares separations of similar samplesobtained with these four rotor designs. Run times forthe rate zonal method were calculated to provide thebest resolution for each rotor. Additionally, the rotorinstruction manuals were used to obtain optimumrotor speeds for isopycnic banding of DNA in cesiumchloride (CsCl) gradients.