词条 | Buoyant density centrifugation |
释义 |
Buoyant density centrifugation (also isopycnic centrifugation or equilibrium density-gradient centrifugation) uses the concept of buoyancy to separate molecules in solution by their differences in density. ImplementationHistorically a caesium chloride (CsCl) solution was often used, but more commonly used density gradients are sucrose or Percoll. The sample is put on top of the solution, and then the tube is spun at a very high speed for an extended time, at times lasting days. The CsCl molecules become densely packed toward the bottom, so even layers of different densities form. Since the original solution was approximately the same density, they go to a level where their density and the CsCl density are the same, to which they form a sharp, distinctive band. Isotope separationThis method very sharply separates molecules, and is so sharp that it can even separate different molecular isotopes from one another. DNA separationBuoyant density of majority of DNA is 1.7g/cm3 which is equal to density of 6M CsCl solution. Buoyant density of DNA changes with its GC content. See also
ReferencesFurther reading
2 : Separation processes|Laboratory techniques |
随便看 |
|
开放百科全书收录14589846条英语、德语、日语等多语种百科知识,基本涵盖了大多数领域的百科知识,是一部内容自由、开放的电子版国际百科全书。