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the centrifuge used in ultracentrifugation.
A high-speed centrifuge (up to 100,000 rpm) by means of which large molecules, for example, of protein or nucleic acids, are caused to sediment at practicable rates; used for determinations of molecular weights, separation of large molecules, criteria of homogeneity of large molecules, conformational studies, etc.
A high-velocity centrifuge used in the separation of colloidal or submicroscopic particles.
ul′tra·cen·trif′u·gal (-trĭf′yə-gəl, -trĭf′ə-gəl) adj.
ul′tra·cen′tri·fu·ga′tion (-fyo͝o-gā′shən) n.
A high-speed centrifuge by means of which large molecules (e.g., of protein or nucleic acids) are caused to sediment at practicable rates.
ultracentrifugeA device for rotating small containers at extremely high speed so as to expose the liquid contents to powerful centrifugal force, of the order of 100,000 g. Ultracentrifuges are used to separate particles of molecular size and determine molecular weights.
ultracentrifugea machine capable of spinning a rotor at speeds of up to 50 000 revolutions per minute, producing up to 500 000 g forces. The high speeds enable the separation of tiny particles, which are identified by the rate at which they move down the centrifuge tube. The unit of rate is called the Svedberg (S), after the inventor of the ultracentrifuge. Thus RIBOSOMES are found to consist of two subunits after ultracentrifugation, called 30S and 50S. See also DENSITY-GRADIENT CENTRIFUGATION, DIFFERENTIAL CENTRIFUGATION, MICROSOMAL FRACTION.
A high-speed centrifuge by means of which large molecules sediment at practicable rates.