The Scientist 9[5]:18, Mar. 06, 1995
Tools Centrifuge Improvements Put New Spin On A Laboratory Workhorse By Howard Goldner A true laboratory workhorse, the centrifuge has been an essential part of most biological labs for many years. Using centrifugal force obtained by spinning experimental samples at high revolutions per minute (rpm), the device functions as a preparative method to separate various sample components, within minutes, for further treatment. Ultracentrifugation is an even more powerful technique that is used in analytical studies involving the characterization of and interactions between biological molecules in solution (see story below). Analytical ultracentrifugation (AU) is a remarkable technique pioneered by Teodor Svedberg, a Nobel Prize-winning Swedish chemist, more than 50 years ago that is gaining renewed popularity among many scientists, especially in the pharmaceutical and biotechnology areas. In AU, a high-speed centrifuge or ultracentrifuge rotates macromolecular solutions in excess of 60,000 rpm, inducing sedimentation. The process, followed by either optical absorption or Rayleigh interferometry, accurately characterizes molecules. AU was fashionable in the 1950s and 1960s for use with investigations involving molecular interactions in solution. However, a few hours of lab experiments generally resulted in up to five weeks of data analysis, owing to a lack of adequate computational equipment. But, a combination of computerized instrumentation, user-friendly software, powerful workstations, and more rapid experimental protocols has led to a resurgence in the technique. | |
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