The Differences Between Filtration and Centrifugation
Filtration and centrifugation are both widely used separation techniques for separating desired components from various mixtures. They seem to have a lot in common, so sometimes people get confused about the difference between the two separation methods and even use the wrong separation method in experiments. Today’s article mainly introduces the definitions of filtration and centrifugation and the differences between them.
Filtration is a physical separation technique that allows liquids or gases to pass through certain substances to remove impurities and become pure. It can also be used to separate a component from a mixture by passing the sample through the filter media by pressure or gravity. Generally, sieves, membrane filters, strainers or other porous media are used to filter out unwanted components. The adsorption capacity of the filter medium itself also works at the same time, which can prevent the bacteria in the sample from passing through the pores and complete the purpose of removing impurities. Pipette tips with filter elements use filtration to isolate contamination and protect the pipette tip. This method is often used for solid-liquid separation.
Centrifugation is a method commonly used to separate substances of different densities in mixed liquid samples using centrifugal force. Generally, the supernatant is removed after centrifugation to retain the precipitate. For the thaw and recovery of cell culture, the supernatant is usually removed after centrifugation to remove residual cryoprotectant.
Filtration VS Centrifugation
The main difference between them is the force used and the separation tool used.
- Filtration uses gravity or pressure for filtration and separation. It generally uses porous filter media similar to sieves to filter, and filter media with different densities are selected according to the need for accurate filtration.
- Centrifugation uses the difference in sedimentation of different substances under the influence of centrifugal force for centrifugal separation, and centrifuges are generally used for the centrifugation operation.
- Filtration is to screen different substances through the filter medium by particle size or volume. Centrifugal separation is based on the difference in particle mass for centrifugal separation.
- Filtration is generally to filter out the larger impurities in the mixture, and retain the fluid and small particle mixture. And centrifugation is to sink the denser material to the bottom and keep it, and pour out the lighter liquid left on the top.
- The process of filtration technology is relatively simple but the operation efficiency is low. It takes more time to separate substances, and the separation accuracy is not high. Centrifugal separation has a special machine, which is simple to operate and takes less time to separate, with higher efficiency, faster speed and higher accuracy.
- Filtration is often used in situations where the mixture has a large difference in substance, similar to solid-liquid separation. The mixture with small particles or liquid similar to colloid can be centrifuged. Centrifugation can be used when the filtration rate is very slow.
If you have read this, you must have understood the difference between filtration and centrifugation, and you will be more confident in what situation to use filtration and which situation to use centrifugation in the future. If you need centrifuge tubes, centrifuge bottles or other experimental related consumables, Hawach looks forward to being your partner.