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Svedberg
Non-SI unit for sedimentation coefficients / From Wikipedia, the free encyclopedia
In chemistry, a Svedberg unit or svedberg (symbol S, sometimes Sv) is a non-SI metric unit for sedimentation coefficients. The Svedberg unit offers a measure of a particle's size indirectly based on its sedimentation rate under acceleration (i.e. how fast a particle of given size and shape settles out of suspension).[1] The svedberg is a measure of time, defined as exactly 10−13 seconds (100 fs).
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For biological macromolecules and cell organelles like ribosomes, the sedimentation rate is typically measured as the rate of travel in a centrifuge tube subjected to high g-force.[1]
The svedberg (S) is distinct from the SI unit sievert or the non-SI unit sverdrup, which also use the symbol Sv, and to the SI unit Siemens which uses the symbol S too.