Tuesday, November 13, 2007

Centrifuges are used in many different kinds of laboratories across the world. From research to clinical, industrial, and forensic labs, a centrifuge is used to separate liquids into different components. If you're reading this article, chances are that you need to centrifuge something down or 'spin it down.' Perhaps your lab manager told you to order another centrifuge for the lab because your current capacity isn't enough. Centrifuges can be generally divided into low speed, super speed, and ultra-speed centrifuges. About 95% of all centrifugation is done in the low speed category, generally below 20,000g. It is this category that I would like to concentrate on today. We can furter segment this category into ventilated and refrigerated centrifuges. The refrigeration is used to keep samples cold; usually at 4°C. This is usually done when centrifugating DNA, proteins, or amino acids. Microcentrifugation is usually used for DNA samples since microtubes hold small volumes in the 0.2ml - 2.0ml range. When choosing a centrifuge, several important questions need to be answered. 1)What size tubes will be used in the centrifuge. 2)How many tubes need to be spun at one time. 3)What speed to you need to centrifuge at, and 4)What temperature do you need to keep the samples at. After all these questions are answered, one can start to build a tabletop or floor-model centrifuge for one's needs. So, for example, if you need to spin 30 microtubes at 4°C at 14,000g, one centrifuge that you can use is the Eppendorf 5702R. If you're ever unsure as to how to choose a centrifuge, please contact us and one of our specialists will be happy to help you.