Search results
Results from the WOW.Com Content Network
Percoll was previously used in assisted reproductive technology (ART) to select sperm from semen by density gradient centrifugation, for use in techniques such as in vitro fertilization or intrauterine insemination. However, in 1996, Pharmacia sent out a letter to laboratories stating that Percoll should be used for research purposes only, not ...
Historically a cesium chloride (CsCl) solution was often used, but more commonly used density gradients are sucrose or Percoll.This application requires a solution with high density and yet relatively low viscosity, and CsCl suits it because of its high solubility in water, high density owing to the large mass of Cs, as well as low viscosity and high stability of CsCl solutions.
The centrifugation method has a wide variety of industrial and laboratorial applications; not only is this process used to separate two miscible substances, but also to analyze the hydrodynamic properties of macromolecules. [4] It is one of the most important and commonly used research methods in biochemistry, cell and molecular biology.
Rate-zonal centrifugation is a centrifugation technique employed to effectively separate particles of different sizes. [1] The tube is first filled with different concentrations of sucrose or another solute establishing layers with different densities and viscosities, forming a density gradient, within which the particles to be separated are added.
Such an "equilibrium" centrifugation can allow extensive purification of a given particle. Sucrose gradient centrifugation—a linear concentration gradient of sugar (typically sucrose, glycerol, or a silica based density gradient media, like Percoll)—is generated in a tube such that the highest concentration is on the bottom and lowest on ...
The method is distinguished from zone-sedimentation in that a stabilizing density gradient is self-generated during centrifugation, through the use of a higher density (than the sample) bulk "binary solvent", containing both a solvent (i.e. H 2 O), and a second component (small molecules, i.e. CsCl) that will sediment to form a stabilizing ...
Isopycnic centrifugation refers to a method wherein a density gradient is either pre-formed or forms during high speed centrifugation. After this gradient is formed particles move within the gradient to the position having a density matching their own (this is in fact an incorrect description of the exact physical process but does describe the ...
Isopycnic centrifugation, often used to isolate nucleic acids such as DNA; Sucrose gradient centrifugation, often used to purify enveloped viruses and ribosomes, and also to separate cell organelles from crude cellular extracts; There are different types of laboratory centrifuges: Microcentrifuges