Centrifugation

1. University of Science and Technology,
Korean Research Institute of Bioscience and Biotechnology
Course Instructor: Ji-Seon Jeong
Presenter: Mesele

2. CENTRIFUGATION
 Centrifuge is a device that used to separate various components of fluid.
 Achieved by spinning the fluid at high speed with in a container, thereby
separating fluids of different densities.
 In biology the particles are usually cells, subcellular organelles, or large
molecules.
A laboratory centrifuge
 is a laboratory equipment
 Driven by motor
 spine liquid at high speed
 Separate substance of greater and lesser density

3. PRINCIPLE
 Rate of settling of a particle, or the rate of separation of two immiscible liquids, is increased
many times by the application of a centrifugal field (force) many times that of gravity.
 Works using sedimentation principle, where centripetal acceleration causes denser
substances and particle to move outward.
 Consists of rotor containing two, four, six, or many other numbered walls with in which the
sample containing centrifuge tips may be placed.

4. BIOSEPARATIONS
• Separating and purifying biological materials
• Filtration and centrifugation
• Chromatography and electrophoresis also common methods

5. SUPERNATANT AND A PELLET
• Supernatant is the liquid at the top that are less dense are dispel the center
• Pellet is particles stuck at the bottom of centrifuge tubes

7. MANY APPLICATIONS
• Separate two immiscible liquids
• Isolate cellular organelles
• Isolate DNA, RNA, and proteins
• Isolate small particles including
• Bacteria
• Viruses
• Cells

8. FORCE IN A CENTRIFUGE IS PROPORTIONAL TO TWO THINGS
• 1st, it depends on how fast
the centrifuge spins
• 2nd, it depends on the radius
of rotation – think about
“crack the whip”

9. SAFETY!!
• Centrifuges look sturdy, sort of like washing machines
• But, they are probably the most dangerous instrument any of you will
use
• Also surprisingly easy to damage
• BE CAREFUL!!!!!
• Purchase the correct rotors for your application
• Balance, balance , balance

11. why we use centrifuge
 Separation of mixtures with close densities
 Separate immiscible liquids (e.g.. Oil and water)
 Sediment suspended solids (e.g.. Sand and water)
 Separation of blood
 Separation of insoluble particles (e.g.. Insoluble
proteins in a protein solution)