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🔹Centrifuge is a laboratory device that is used for the separation of fluids, gas or liquid, based on density.🔹It uses centrifugal force to separate the contents of a sample based on their density.🔹Separation is achieved by spinning a vessel containing material at high speed🔹When the centrifuge spins, it creates a strong centrifugal force.🔹Though separation would eventually happen naturally with Earth’s gravity🔹The centrifuge machine delivers rapid results for laboratory and other applications.🔹The centrifugal force pushes heavier materials to the outside of the vessel.🔹In a solution, particles whose density is higher than that of the solvent sink (sediment)🔹Particles that are lighter than it float to the top.🔹If there is no difference in density (isopyknic conditions) the particles stay steady.🔹To take advantage of even tiny differences in density to separate various particles in a solution, gravity can be replaced with the much more powerful centrifugal force provided by a centrifuge.🔹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. Principle of Centrifuge Machine🔹A centrifuge works by using the principle of sedimentation🔹Under the influence of gravitational force substances separate according to their density🔹It generally driven by an electric motor, that puts an object, 🔹A rotor, in a rotational movement around a fixed axis. What is Centrifugation?🔹Centrifugation 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 test tube.🔹Centrifugation can occur with either filtration or sedimentation methods.🔹Filtration uses a mesh screen to hold back the solid components and allow the liquid components to flow through.🔹Filtering does not work to centrifuge blood samples because the blood components are too small.🔹In either method, the particles are suspended in liquid and separated in the centrifuge machine.🔹The separation happens due to centrifugal force, which pushes objects outward toward the tip of the tube,in the case of blood tubes – as they are spun around in a circle🔹centrifugation is separation through sedimentation 🔹The denser particles sink to the bottom of the container, while the more lightweight particles remain suspended. 🔹Centrifugation will displace particles that are even slightly different in density Centrifugation is influenced by these following factors◾The density of the samples and solution ◾The temperature and viscosity ◾The distance that the particles are displaced ◾The speed of rotation What is centrifugation used for?🔹Centrifuge machines are excellent at separating particles by density🔹They are often used in laboratories 🔹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 component🔹Separating out blood plasma for testing, isolating DNA 🔹Separating out urine sediments What are the different parts of centrifuge?🔸Rotor🔹The design of most centrifuges allows the drive system to accept rotors of different sizes and capacities 🔸Motor🔹In general, centrifuge motors are high-torque, series-wound DC motors🔹The rotation of which increases as the voltage is increased.🔹Electrical contact to the commutator is provided by graphite brushes, which gradually wear down as they press against the commutator turning at high speed, and thus should be replaced at specified intervals. 🔹Modern centrifuges have induction drive motors that have no brushes to change. 🔸Imbalance Detector🔹Some of the instruments have an internal imbalance detector that monitors the rotor during operation, 🔹It causing automatic shutdown if rotor loads are severely out of balance. 🔸Tachometer🔹A tachometer indicates the speed in rpm. 🔹Safety Lid🔹Modem centrifuges must have a door-locking mechanism to prevent the lid from being opened while the instrument is running. 🔸Refrigerator🔹A centrifuge generates heat as it rotates and if samples are temperature labile then a refrigerated centrifuge should be used. How a centrifuge work?🔹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 differentangles based on the types🔹Depending on the centrifuge, the tubes may either be loaded at the angle🔹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🔹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🔹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 mas 🔹Ensure your centrifuge receives the proper care and maintenance so it provides accurate separation Education to the user🔹Make sure that everyone who uses the centrifuge machine knows how to use it.🔹Teach all laboratory staff how to balance samples, set speeds and take safety measures🔹All employees are to be instructed in the proper use of the centrifuge before being allowed to operate it. 🔹All employees must follow universal precautions when operating or cleaning the centrifuge. Inspection🔹 An inspection will alert you to any problems with the centrifuge machine. 🔹Look at the components for scratches or effects of chemical exposure. Awareness🔹When using the centrifuge, be aware of signs that something is wrong.🔹If the machine is shaking, vibrating or grinding, stop it immediately.🔹Cleaning and disinfection are key to ensuring good centrifuge functionality in the long term.🔹Using a neutral cleaning solution (like an alcohol-based disinfectant) and a soft cloth, wipe the◾ Rotors◾Rotor chamber◾Accessories◾Interior area◾Keypads ◾Touch screens Instruction for User🔹Load an equal number of test tube cups, cup cushions and specimen tubes of equal size and weight, arranging them symmetrically inside the rotor head.🔹An unbalanced load will cause poor specimen separation, excessive noise and vibration, and will result in increased wear on the rotor.🔹Keep the centrifuge closed and locked during operation.🔹Refer to the instrument manual for on-off operation instructions.🔹Do not use your hand or any mechanical device to stop the rotor.🔹If unusual noises or vibrations occur during operation of the centrifuge, immediately turn off the centrifuge🔹Use the power brake to slow down the rotor until completely stopped.🔹Unplug the unit and, using caution to guard against any sharps hazard🔹Identify and eliminate the source of the problem, if possible. 🔹The operator is responsible for the condition of the machine at the end of each use (i.e., turning off the power, cleaning up spills, etc). What are the different types of Centrifuges?🔹There are many types of centrifuges, varying by intended use and rotor design ◾Micro Centrifuge🔹As the name suggests, these are extremely compact in design and, therefore, have a smaller footprint that takes up little space on the workbench.🔹These are apt for use with small tubes (up to 2.0 ml) and often find use in biological application 🔹These are used for holding pelleting nucleic acids, and for pelleting proteins from solutions as well as microfiltration of minor aqueous samples. ◾Refrigerated Centrifuge🔹These are used for samples that need to be stored at a consistent temperature.🔹It is important that these centrifuges function at maximum speeds while maintaining a steady temperature. 🔹The temperature range of refrigerated centrifuges is between -20 and -40 degrees Celsius, which makes them perfect for analyzing DNA, RNA, PCR, and antibodies. ◾High Speed Refrigerated Centrifuge🔹Among the different types of centrifuges, these ones can produce substantial force for gathering cellular debris, micro-organisms, larger cell organelles, and proteins. ◾Ultra Centrifuge🔹These centrifuges can generate acceleration of up to 1,000,000 g, which is extremely high. |
Spins samples at high speed, which allows lighter components to float to the top and heavier components to sink to the bottom
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