Using GLUT

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UNIT 2 CENTRIFUGE

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3.0 MAIN CONTENT 3.1 CENTRIFUGE

Diagram of centrifuge www.researchgate.com

A centrifuge is a piece of equipment that puts an object in rotation around a fixed axis (spins it in a circle), applying a force perpendicular to the axis of spin (outward) that can be very strong.

The centrifuge works using the sedimentation principle, where the centrifugal 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.

TYPES

There are three types of centrifuge designed for different applications. Industrial scale centrifuges are commonly used in manufacturing and waste processing to sediment suspended

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solids, or to separate immiscible liquids. An example is the cream separator found in dairies.

Very high speed centrifuges and ultracentrifuges able to provide very high accelerations can separate fine particles down to the nano-scale, and molecules of different masses.

Large centrifuges are used to simulate high gravity or acceleration environments (for example, high-G training for test pilots). Medium-sized centrifuges are used in washing machines and at some swimming pools to wring water out of fabrics.

Gas centrifuges are used for isotope separation, such as to enrich nuclear fuel for fissile isotopes.

Bench top Centrifuges are a broad class of centrifuges characterized by their small bench space footprint. Depending on the research need, a variety of different aspects can be considered.

Maximum speed in RCFs can range from as low as a few hundred to to over 50,000 x g. Tube volumes can range from under 1 mL (such as with PCR tubes) to a few liters. Different types of rotors such as fixed angle, swinging bucket, and continuous flow are also typically interchangeable. Check out our diverse listings of bench top centrifuges.

Refrigerated Bench top Centrifuges are compact instruments ideal for centrifugation of samples that may be temperature sensitive, such as live cells, animals or proteins. Many feature interchangeable rotors and adaptors to accommodate a wide range of sample volumes from under 1 mL to a few liters. Speeds can also vary, and some models can reach up to 60,000 x g.

Check out the different refrigerated bench top centrifuges currently on the market.

Clinical Bench top Centrifuges are compact, low-speed centrifuges ideal for the separation of whole blood components, such as serum, plasma, Buffy coat, red blood cells, as well as other bodily fluids. Their speeds may range between around 200 rpm to 6,000 rpm. Most clinical centrifuges can accommodate common blood draw tubes, but be sure to check with each vendor for specific tube sizes or tube adaptors. Check out a variety of clinical benchotop centrifuges from different manufacturers.

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Micro-centrifuges are staple instruments in many research laboratories that generally accommodate small tube volumes such as 2 mL, 1.5 mL, 0.5 mL and PCR tubes. Micro-centrifuges for routine laboratory procedures typically spin at speeds up to 16,000 x g, while more specialized instruments can reach speeds up to 30,000 x g. In addition, manufacturers may also offer interchangeable rotors and tube adaptors. Compare a variety of different ambient temperature micro-centrifuges and refrigerated micro-centrifuges.

Vacuum Centrifuges / Concentrators can use vacuum, centrifugal force, temperature and/or gas to remove liquid solvent for the concentration or desiccation of samples. This instrument is ideal for purification or preparation of samples such as nucleic acids, proteins, peptides, and other compounds for a variety of research applications. For evaporation of solvents, vacuum centrifuges typically utilize built in heating systems. Check out different vacuum centrifuges or concentrators here.

4.0 CONCLUSION

In this unit, you have learnt about the centrifuge as a laboratory device. The centrifuge is used in the laboratory for the separation of suspension.

5.0 SUMMARY

The spinning action of the centrifuge separates materials on the principle of heavier objects or materials falling to the bottom. It finds great use also in different aspects of medical and laboratory research

6.0 TUTOR-MARKED ASSIGNMENT

- List any four types of centrifuge you know - What are the uses of centrifuge?

Solution

- List any four types of centrifuge you know Industrial scale centrifuges

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Large centrifuges Gas centrifuges

- What are the uses of 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 force perpendicular to the axis of spin (outward) that can be very strong.

The centrifuge works using the sedimentation principle, where the centrifugal 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.

7.0 REFERENCE/FURTHER READING

Hjelm, M, (1975) The use of ’push the button’ analysers in clinical chemistry.

Organisation des Laboratoires-Biologie Prospect-ive. III^e Collogue de Pont-a- Mousson, L’expansion Scientifique Francaise, p.11.

Susan R. Mikkelsen & Eduardo Cortón. Bioanalytical Chemistry, Ch. 13. Centrifugation Methods. John Wiley & Sons, Mar 4, 2004, pp. 247–267.

Heidcamp, Dr. William H. "Appendix F". Cell Biology Laboratory Manual. Gustavus Adolphus College,. Retrieved 11 March 2012.

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Unit 3: PORTABLE OPTICAL AIR SENSOR