Equilibrium ultracentrifuge for molecular weight measurement
β Scribed by Beams, J. W. ;Boyle, R. D. ;Hexner, P. E.
- Book ID
- 104532081
- Publisher
- John Wiley and Sons
- Year
- 1962
- Weight
- 764 KB
- Volume
- 57
- Category
- Article
- ISSN
- 0022-3832
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β¦ Synopsis
Abstract
The magnetically supported vacuumβtype equilibrium ultracentrifuge previously described has been improved and used for the measurement of the molecular weights of a number of substances. The modifications include an electric motor drive which accelerates the rotor to operating speed. The rotor coasts freely during the sedimentation, and the operating speed may have any desired value from a few revolutions per second to the maximum safe speed of the rotor. Improvements have been made in the ultracentrifuge cell, and both white light and monocromatic light fringes can be used interchangeably in the interferometer. These modifications make possible the determination of the molecular weight quickly either without waiting for equilibrium to take place or after equilibrium has been established. The overall precision is the order of one part in a thousand for the centrifuge measurements themselves. Molecular weight data are given for a number of substances, including sucrose, ribonuclease, and insulin. The application of the centrifuge to the determination of molecular weight distributions is discussed.
π SIMILAR VOLUMES
High-molecular-weight kininogen, a nonenzymatic glycoprotein of the intrinsic blood coagulation system, is proteolytically cleaved by kallikrein as an early event in the activation of this system. The light chain of cleaved kininogen retains the ability to form specific noncovalent complexes with pr
## Abstract A method is outlined for the determination of molecular weights and molecular weight distributions in linear, neutral polymers from boundary spreading data obtained from the ultracentrifuge. By use of the intrinsic viscosity, and having knowledge of its molecular weight dependence, it i