In this article, you will be taken through some of the basic parts of Centrifuge and their functions just as needed in the lab or where it becomes scientifically possible or useful.
A centrifuge is a laboratory device that is used for the separation of fluids, gas or liquid, based on density. Separation is achieved by spinning a vessel containing material at high speed; the centrifugal force pushes heavier materials to the outside of the vessel. This apparatus is found in most laboratories from academic to clinical to research and used to purify cells, subcellular organelles, viruses, proteins, and nucleic acids.
There are two basic components to all centrifuges, the rotor assembly and the electrical motor. The rotor assembly is that part of the centrifuge which transfers the rotation motion produced by the electrical motor. Included in the rotor assembly are tube holders and the drive shaft, which converts energy from the motor to the end point application. The motor is the device that converts electrical energy to mechanical energy and produces the rotational motion.
The Different Basic Types of Centrifuges
Before you get to know some of the basic parts of centrifuge and their functions, it will even be a good idea if you have the chance to know some of the different basic types of this unique scientific machine or device:
- Benchtop 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.
- Refrigerated Benchtop 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.
- Clinical Benchtop Centrifuges: They 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.
- Microcentrifuges: They 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. Microcentrifuges 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.
- Vacuum Centrifuges / Concentrators: It 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.
Basic Parts of Centrifuge and their Functions
A centrifuge can be a very effective filter that separates contaminants from the main body of fluid. 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. The commonly known basic parts of centrifuge and their functions are hereby put very simply for you to look through:
1. Electric Motor
Electric motor is a part of the centrifuge which helps to drive.
2. Control Panel
The control panel placed on the front casing serves the purpose of controlling centrifuge operation.
3. Chamber
The entire system is housed within a chamber. The centrifuge head contains the cups or shields that cover the rotor and turns on a spindle. A safety shield in the chamber surrounds the rotors.
4. Rotor
Rotors in centrifuges are the motor devices that house the tubes with the samples. Centrifuge rotors are designed to generate rotation speed that can bring about the separation of components in a sample. There are three main types of rotors used in a centrifuge, which are:
- Fixed Angle Rotors: Here, its tubes are held at an angle of 14 to 40°to the vertical. Particles move radially outwards, travel a short distance. It is useful for differential centrifugation and the reorientation of the tube during acceleration and deceleration of the rotor.
- Vertical Rotors: It is usually held vertical parallel to the rotor axis. Particles move short distances. The time of separation is shorter. The demerit of this, the pellet may fall back into the solution at end of centrifugation.
- Swinging Bucket Rotors/ Horizontal Rotors: This one swings out to horizontal position when rotor accelerates. A longer distance of travel may allow better separation, such as in density gradient centrifugation. Easier to withdraw supernatant without disturbing pellet. Normally used for density-gradient centrifugation.
5. Latch
Discontinue use of any centrifuge that does not have a latch; the latch keeps the centrifuge lid closed in the event of tube breakage or other problems while the centrifuge is operating. All such units should be replaced or modified to include a latch; contact the manufacturer for information.
6. The Interlocks
If available, purchase centrifuges that have lids with interlocks to prevent the user from opening the lid while the rotor is spinning.
7. Lid
Discontinue the use of any centrifuge that does not have a lid and does not retrofit the unit with a lid that does not have a latch. When possible, purchase centrifuges that have inner safety lids for the buckets or rotor. If the units being purchased allow the outer lid to be opened while the rotor is spinning at low speeds, be sure they have protective inner lids.
