CENTRIFUGE

Prepared ByName: Pankaj NaliyaparaRoll Number: 603142

L.D. College of EngineeringBiomedical Engineering Department

Ahmedabad-15

CONTENT●History●Introduction●Principle●Types●Procedure●Application●Safety

HistoryEnglish military engineer Benjamin Robins (1707–1751) invented a whirling arm apparatus to determine drag.

In 1864, the first dairy centrifuge in order to separate cream from

milk.

In first continuous centrifugal separator,

making its commercial

application feasible

INTRODUCTION DEFINATION “THE DEVICE USE TO SEPARATE HEAVIER PARTICLES FROMTHE LIGHTER ONE BY THE ACTION OF CENTRIFUGAL FORCE.”

●The principle component of a centrifuge is the rotor, which is the moving part that spins at high speeds.

●Rotors can be fixed in position, or a centrifuge can use multiple rotors fixed atop part called the spindle.

PRINCIPLE● The centrifuge works on the principle of increasing effective gravity to enhance the rate of settling of suspended particles more dense than the buffer.

● we need to double the force on samples, increase the rotation speed by 41%.

● After centrifuging, the liquid is called "supernatant“ and the solids at the bottom of tube are called "pellet".

● Centrifugal force :-

“a force, arising from the body's inertia, which to act on a body moving in a circular path and is directed away from the centre around which the body is moving.”

TYPES

Fixed-angle

Swinging head

Continuous tubular

types by rotor design

types by intended use

Ultracentrifuges

Hematocrit

Gas centrifuge

●Fixed-angle :-Fixed angle rotor centrifuges are probably the most common type of this instrument encounter in the lab. These centrifuges, in which tubes sit in a fixed and angled position, are used in differential centrifugation protocols. In these protocols, a series of centrifugations at different speeds can be used to purify biological specimens like animal cells.

● Ultracentrifuges :- It can spin in excess of 70,000 rpm, which makes it well suited for the isolation of small particles, like DNA or viruses.

10MLI-mde 210, 311

Centrifuge tubes

• Glass centrifuge tubes can be used with most solvents, but tend to be more expensive. They can be cleaned like other laboratory glassware, and can be sterilized by autoclaving.

• Plastic centrifuge tubes, especially micro-centrifuge tubes tend to be less expensive. Water is preferred when plastic centrifuge tubes are used. They are more difficult to clean thoroughly, and are usually inexpensive enough to be considered disposable

11MLI-mde 210, 311

Centrifuge tubes

Three microcentrifuge tubes: 2 mL, 1.5 mL and 200 μL .

Four screw-top micro-centrifuge tubes.

PROCEDURE

Centrifugation is a process by which a centrifuge is used to separate components of a complex mixture.

By spinning laboratory samples at very high speeds, the components of a given mixture are subjected to centrifugal force, which causes more dense.

particles to migrate away from the axis of rotation and lighter ones to move toward it. These particles can sediment at the bottom of the tube into what’s known as a pellet or the remaining solution, the supernatant, can be further process.

Centrifugation of blood●A centrifuge separates out blood components by their various densities.

●The red blood cells (RBCs) are denser and move to the bottom of the tube.●The plasma fraction is the least dense and will float as the top layer.

EXAMPLE

●The plasma fraction is the least dense and will float as the top layer.

●The "buffy coat“ which contains the majority of platelets will be sandwiched between the plasma and above the RBCs.

APPLICATIONS

●Removing fat from milk to produce skimmed milk.● Removing water from lettuce after washing it in a salad spinner.● Separating particles from an air-flow.● For clarification and stabilization.● Separation of water particles from clothes while spin-drying in washing machines.● Separation of urine components and blood components in forensic and research labs.

CENTRIFUGE SAFETY● Ensure that centrifuge bowls and tubes are dry.● Ensure that the spindle is clean● Ensure that the rotor is properly seated on the drive shaft.● Make sure that tubes or containers are properly balanced in the rotor.● Do not exceed the rotor’s maximum run speed.● Close the centrifuge lid during operation.● Make sure that the centrifuge is operating normally before leaving the area.● Make sure that the rotor has come to a complete stop before opening the lid.

VIDEO