Manorma negi
Download as PPTX, PDF1 like616 views
Centrifugation uses centrifugal force to separate mixtures based on density. There are three main types of centrifuges - low-speed centrifuges which operate under 4000-5000 rpm, high-speed centrifuges which operate at higher speeds and temperatures, and ultracentrifuges which operate at very high speeds under vacuum. Centrifugation is used in industry and laboratories to separate dense and less dense components of mixtures through sedimentation.
Manorma negi
- 2. Student Name: Manorma Negi Food technology 4th semester Topic: Centrifugation
- 3. Centrifugation • Its Principle Types of Centrifuges & Its Uses & Characteristics • Applications • Instrumentations for Centrifugation • Bibliography
- 4. Centrifugation is a procedure that involves the use of centrifugal force for the sedimentation of mixture with a centrifuge used in industry and in laboratory settings. More dense components of the mixture move away from the axis of the centrifuge while less dense components of the mixture move towards the axis
- 5. .The centrifugal force F is denoted by equation F=mω2 r Where F= intensity of the centrifugal force m= effective mass of the sedimenting particle ω= angular velocity of rotation r= distance of the migrating particles from the central axis of rotation A more common measurement of F in terms of the earths gravitation force , g, is relative centrifugal force, RCF its defined by RCF = (1.119 x 10-5 (rpm)2 (r) This equation relates RCF to revolutions per minute of the sample . Equation dictates that the RCF on a sample will vary with r, the distance of the sedimenting particles from the axis of rotation . The RCF value is reported as “ a number times gravity ,g .”
- 6. A laboratory tabletop centrifuge. The rotating unit, called the rotor, has fixed holes drilled at an angle (to the vertical). Test tubes are placed in these slots and the motor is spun. As the centrifugal force is in the horizontal plane and the tubes are fixed at an angle, the particles have to travel only a little distance before they hit the wall and drop down to the bottom. These angle rotors are very popular in the lab for routine use.
- 7. The basic centrifuge consists of two components one is Electric motor with drive shaft to spin the sample and a Rotor to hold tubes or other containers of the sample. There are three types of centrifuges 1.Low –speed centrifuges . Its also called as clinical centrifuge. The common centrifuge has a maximum speed in the range of 4000 to 5000 rpm with RCF . These instruments usually operate at low temperature . Two types of rotors fixed angle and swinging bucket may be used in this instruments. continue….
- 8. Low speed centrifuges are especially useful for the rapid sedimentation of coarse precipitates or red blood cells. The sample is centrifuged until the particles are packed into a pellet at the bottom of the tube. The upper liquid portion, the supernatant, is then separated by decantation.
- 9. 2. High Speed Centrifuges: High speed centrifuges for more sophisticated biochemical applications. Higher speeds and temperature control of the rotor chambers are essential. Rotor chambers in most instruments are maintained at or near 40 C. Three types of rotors are available for high speed centrifugation. a. Fixed Angel rotor. b. Swinging –bucket rotors c. vertical rotor High speed centrifuges are used to sediment
- 11. 3. Ultracentrifuge s: >> The most sophisticated of the centrifuges are the ultracentrifuges because of the high speeds attainable intense heat is generated in the rotor so the spin chamber must be refrigerated and placed under high vacuum to reduce friction. >> it is a high speed centrifuge that has fixed head rotors .It is mainly used in separation of lipoproteins . >> Ultracentrifuges can be used both for preparative work as well as for analytical.
- 13. Schematic presentation of a laboratory centrifuge:
- 14. Preparative Techniques Centrifuges in undergraduate biochemistry laboratories are used most often for preparative – scale separation . The sample is removed and the two phases ,pellet and supernatant may be separated. further characterization or analysis is usually carried out on the individual phases . This technique called as velocity sedimentation centrifugation, separates particles ranging in size from coarse precipitates to cellular organelles .
- 15. * Modern Experimental Biochemistry By BOYER * Biotechnology by U. Satyanarauana * Internet