CENTRIFUGATION.ppt
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Centrifugation is a technique used to separate substances of different densities. It involves applying centrifugal force using a centrifuge, which spins samples at high speeds. This causes denser particles to sediment to the bottom of tubes while less dense particles rise to the top, allowing for separation. Centrifugation is used in processes like separating cream from milk, separating blood components, and purifying proteins and cells. It works on the principle that density differences between particles or molecules can be exploited to separate mixtures.
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CENTRIFUGATION.ppt
- 1. CENTRIFUGATION SUBMITTED BY A.AARTHI I M.SC BIOTECHNOLOGY UNDER THE GUIDANCE DR.R.KALAIVANI ASSISTANT PROFESSOR OF BIOTECHNOLOGY BON SECOURS COLLEGE FOR WOMEN, THANJAVUR
- 3. CENTRIFUGATION Centrifuge was invented by svedberg in 1920 Centrifugation is a technique of separating substances which involves the application of centrifugal force. The particles are separated from a solution according to their size, shape, density, the viscosity of the medium and rotor speed. Centrifugationis the process where a mixture is separated through spinning. It is used to separate skim milk from whole milk, water from your clothes, and blood cells from your blood plasma.
- 5. CENTRIFUGATION RPM stands for Rotation Per Minute. The rotor is the rotating portion of the centrifuge that is rotated by the motor. The number of complete rotations that a rotor makes in a minute is known as RPM. The RPM of the centrifuge can range from around 300 – 1,50,000. So, based on the necessity (application), various centrifuge machines have been designed. Relative centrifugal force (RCF) refers to the amount of force applied when using a centrifuge. To convert revolutions per minute (RPM) to relative centrifugal force (RCF), or g force, use the following formula: RCF = (RPM)2 × 1.118 × 10-5 × r
- 6. Centrifugation principle In a solution, particles whose density is higher than that of the solvent sink (sediment), and particles that are lighter than it floats to the top. The greater the difference in density, the faster they move. If there is no difference in density (isopycnic conditions), the particles stay steady. To take advantage of even tiny differences in density to separate various particles in a solution, gravity can be replaced with the much more powerful “centrifugal force” provided by a centrifuge. A centrifuge is a piece of equipment that puts an object in rotation around a fixed axis (spins it in a circle), applying a potentially strong force perpendicular to the axis of spin (outward).
- 8. The centrifuge works using the sedimentation principle, where the centripetal acceleration causes denser substances and particles to move outward in the radial direction. At the same time, objects that are less dense are displaced and move to the center. In a laboratory centrifuge that uses sample tubes, the radial acceleration causes denser particles to settle to the bottom of the tube, while low- density substances rise to the top.
- 10. Parts of Centrifuge Motor: Electric motor is a part of the centrifuge which helps to drive. Control Panel: The control panel placed on the front casing serves the purpose of controlling centrifuge operation. Chamber: The entire system is housed within a chamber. The centrifuge head contains the cups or shields that cover the rotor and turns on a spindle. A safety shield in the chamber surrounds the rotors. Sample: That to be separated. Latch: Discontinue use of any centrifuge that does not have a latch; the latch keeps the centrifuge lid closed in the event of tube breakage or other problems while the centrifuge is operating.
- 11. Lid: Discontinue the use of any centrifuge that does not have a lid and does not retrofit the unit with a lid that does not have a latch. Rotor: Rotors in centrifuges are the motor devices that house the tubes with the samples. Centrifuge rotors are designed to generate rotation speed that can bring about the separation of components in a sample. There are three main types of rotors used in a centrifuge, which are: Fixed angle rotors,Vertical rotors and Swinging bucket rotors/ Horizontal rotors. Fixed angle rotors-Tubes are held at an angle of 14 to 40°to the vertical. Particles move radially outwards, travel a short distance. Useful for differential centrifugationReorientation of the tube during acceleration and deceleration of the rotor. Vertical rotors-Held vertical parallel to the rotor axis. Particles move short distances. The time of separation is shorter. The demerit of this, the pellet may fall back into the solution at end of centrifugation. Swinging bucket rotors/ Horizontal rotors- Sing out to horizontal position when rotor accelerates. A longer distance of travel may allow better separation, such as in density gradient centrifugation. Easier to withdraw supernatant without disturbing pellet. Normally used for density-gradient centrifugation.
- 13. Operating procedures Turn on the centrifuge. Set up the parameters,speed,time, temperature, accelerate and decelerate speed Open the centrifuge door. Install the rotors with O-ring that contains balanced bottles or tubes. Make sure the rotor is property seated to the drive hub Secure the rotor with lid,close the centrifuge door. Press enter then the run / start. Wait until reaching the desired speed After Completely stopped, open the door and take out the sample bottles or tubes.
- 14. Types Of Centrifugation PREPARATIVE CENTRIFUGATION Differential Pelleting (differential centrifugation) Density Gradient Centrifugation 1.Rate-Zonal Density-Gradient Centrifugation 2.Isopynic Centrifugation ANALYTICAL CENTRIFUGATION Ultra Centrifugation
- 16. Application of Centrifugation Purification of mammalian cells Fractionation of subcellular organelles (including membranes/membrane fractions) Fractionation of membrane vesicles Separating chalk powder from water Removing fat from milk to produce skimmed milk Separating particles from an air-flow using cyclonic separation The clarification and stabilization of wine Separation of urine components and blood components in forensic and research laboratories Aids in the separation of proteins using purification techniques such as salting out, e.g. ammonium sulfate precipitation.
- 17. Advantages Centrifuge have a clean apperance and have little to no odor problem. The device is simple to Operate. They can be selected for different applications Centrifuge have more process flexibility and higher levels of performance
- 18. Disadvantages The machine can be very noisy and can cause vibration The device has high energy consumption due to high gravitational force High initial capital costs