A centrifuge machine
It is a device that uses centrifugal force to separate various components of a fluid. It is achieved by spinning the fluid at high speed
within a container thereby separating fluids f different density.
It works by causing denser substance and particles to move outward in a radial direction, at the same time objects that are less dense are displayed and move to the centre.
It can be a very effective filter that separates contaminants from the main body of the fluids.
What is centrifugation
It is the process of concentrating the natural forces that act on all particles of different densities to accelerate the natural process of separation. It is what separates the particles by density in the tube.
Principle of centrifugation
At its core, centrifugation is separation through sedimentation, the denser particles sink to the bottom of the container while the more light weight particles remain suspended.
centrifugation will displace particles that are even slightly different in density, it is influenced by the following factor:
the density of the sample and solution
temperature and viscosity
the distance that the particles are displaced
the speed of rotation
Relative centrifugal force or G-force is the amount of acceleration that is applied to the sample, the particle will move away from the axis of rotation and result in sedimentation
What Is a Centrifuge Used For?
Because centrifuge machines are excellent at separating particles by density, they are often found in laboratory settings where it is necessary to isolate certain biological components for testing. In a blood sample, for instance, there are red blood cells and plasma mixed together. After centrifugation, the red blood cells will be at the bottom of the tube and the plasma will be on top.
Centrifuging is necessary for research on particular components, such as separating out blood plasma for testing, isolating DNA, and even separating out urine sediment.
How Does a Centrifuge Work?
The purpose of the centrifuge machine is to replicate and accelerate centrifuging to separate components in a sample. Because of the forces involved, these machines are carefully designed to work efficiently while keeping the operator safe.
The Parts of the Centrifuge Machine
At the center of the centrifuge is a powerful motor that creates the spin. Attached to this motor is the rotor, in which will rest the containers that hold the tubes containing the material to be centrifuged. These containers may be spun at a 45-degree angle (fixed angle centrifuge), a 90-degree angle (horizontal centrifuge) or no angle (vertical centrifuge). Depending on the centrifuge, the tubes may either be loaded at the angle on which they will rotate (fixed angle is a good example of this) or be loaded into a container that will adjust itself to a different angle upon startup. This second methodology is referred to as swing bucket and is a common functionality in horizontal centrifuges.
Depending on the centrifuge selected, a variety of different controls may be available. Some centrifuges are pre-programmed for one, two, or three processing settings. Some are completely custom programmable with a digital display. Regardless of the control type, when you start the centrifuge, it will run the motor based on the settings provided. During the cycle, the sample in the test tubes will separate into their various components so they are ready for analysis.
How to Use a Centrifuge Machine
Despite the complex principles at work in the centrifuge, operating the machine itself is quite simple. To use a centrifuge machine:
- Insert the test tube sample into one of the portals
- If needed based on the number of samples you are testing, insert test tubes filled with water for balance
- Secure the lid and select desired settings
- Start the centrifuge and wait for it to complete the cycle
- When the centrifuge has stopped spinning, take out the balances and samples
- Each sample will now be separated into its various components and ready for analysis
Knowing how a centrifuge machine works is key to using it properly.
Balancing the Centrifuge Machine
When using a centrifuge machine, it is necessary to balance your samples. Balance the centrifuge machine by:
- Making sure all tubes are evenly filled with liquids similar in density
- Ensuring that the masses of the tubes are within 0.1 grams of each other
- Placing tubes opposite from one another inside the machine to keep the gravity in the center
When you test an odd number of tubes, it may not be possible to create balance. In these cases, fill another test tube with water and balance based on density and mass.