Centrifuge Tubes are among the most frequently used tools in labs. They are used for various purposes, from separating blood components to isolating nucleic acids and purifying proteins.
Choosing the right tube for your application is essential for obtaining accurate results and optimizing experimental performance. Adhering to proper handling and storage protocols is also important for longevity and effectiveness.
Centrifuge tubes are laboratory tools used to isolate nucleic acids. They come in a variety of shapes, capacities and materials to suit different needs and applications. They also have different closure types, and some are available in sterile or non-sterile formats. They are a critical component of most laboratory equipment and can help with the smooth operation of many processes.
Centrifugation uses the principle of centrifugal force to separate components of a mixture based on their density. The denser particles move towards the bottom of the tube while the lighter ones rise to the top. This separation is necessary to ensure that the samples are clean and free of contaminating material. It also ensures that the sample can be analyzed correctly.
To isolate nucleic acids from cells, the cell lysate is first centrifuged to separate the proteins and other molecules into organic and aqueous layers. The organic layer contains lipids and proteins, while the aqueous phase is where the nucleic acids are located. A phenol extraction is then carried out to remove any remaining protein from the sample. The resulting nucleic acid is then ready for analysis.
The centrifuge tubes you select should be made of a material that can withstand the conditions of your experiment. Polypropylene (PP) is a common choice as it can handle high speeds and is resistant to most organic solvents. Other options include glass, polycarbonate and stainless steel tubes. PP offers the best corrosion resistance to methanol and ethanol, while polycarbonate and glass offer good chemical resistance to most solutions.
Centrifuge tubes are also available in a variety of shapes, sizes and colors to meet specific application requirements. Some have printed graduations that are easy to read, while others feature molded graduations. They may also have different colors to help with sample identification. You should also consider the maximum RCF that a tube can handle when making your selection.
Other factors to consider when choosing a centrifuge tube include the cap type, shape and dimensions of the tube. A screw cap is great for extra security, and snap caps are simple to open and close one-handed. Some caps have dual graduation scales of 0.2mL and 0.5mL for the most precise measurement.
Protein Purification
Centrifuge tubes are some of the most frequently used lab tools around. They’re used for a wide range of applications, including sample storage, cell separation, and more. However, just like any other lab tool, they must be properly managed to ensure accurate results and extend their lifespan.
Centrifugation plays a key role in protein purification protocols, which separate proteins based on their molecular weight. The goal is to remove any contaminating materials from the proteins, so they can be repurposed for use in other experiments. There are several different methods to do this, including sonication, high-pressure homogenization, and mechanical grinding (bead mill). In all these cases, the resulting mixture requires a centrifuge to separate out the desired protein from the debris.
To accomplish this, it is critical to carefully prepare the sample. For example, the protein must be separated from the cellular debris that contains it. This can be accomplished by adding a centrifuge-compatible buffer to the sample and then homogenizing it. A homogenizer is a mechanical device that pumps a slurry of cellular material through a restricted orifice valve, which causes three mechanisms of disruption: impingement on the valve; high liquid shear within the orifice; and sudden pressure drop upon discharge.
Once the protein is isolated from the cellular debris, it can be further processed by adding it to a column and washing away any contaminating materials. This is a crucial step for repurposing the protein for future use, as the proteins can be contaminated by many different chemicals.
Centrifuge tubes come in a variety of volume capacities, shapes, materials, and RCF ratings. The choice depends on the type of samples you’re testing and how much centrifugation G-force you need to achieve. For example, Globe’s GreenMAX centrifuge tubes are made in a Class 10,000 cleanroom and are tested free from RNase, DNase, human DNA, endotoxins, and PCR inhibitors, which makes them ideal for environmental laboratories. They also feature a large writing surface and tamper-proof graduations, and they’re autoclavable for added safety. You can also choose tubes with a screw cap or snap cap to ensure the lid stays securely in place during centrifugation and prevent leaks.
Choosing the Right Tube
Centrifuge tubes are important for several applications in the laboratory, whether it’s separating blood components, extracting DNA and RNA or purifying proteins. It’s important to choose the right tube for the job, as it can influence results and performance. There are numerous factors to consider when choosing a centrifuge tube for your application, including capacity, material, size and closure type.
Centrifugation involves spinning liquids at high speeds to separate their components. For this reason, it’s crucial to select a container that can stand up to the high-speed spin and will not leak during the process. Centrifuge tubes are typically made from glass or plastic and come in a variety of sizes, ranging from small microcentrifuges to large ultracentrifuge tubes. Often, the tubes have printed or moulded graduations to make it easier to read the contents. They may also be made from a material that resists chemicals or is compatible with the materials of other lab equipment.
Besides being compatible with lab equipment, a centrifuge tube must also be easy to clean and sterilize. This is especially important when working with contaminated samples. The wrong container can damage or clog the instrument, leading to inaccurate data and decreased productivity. Some laboratories use a variety of instruments to analyze their samples, including mass spectrometers and high-pressure chromatography units, which can easily become clogged by extraneous substances that find their way into the machine.
When selecting a centrifuge tube, you must ensure that it fits the rotor of your centrifuge. The tube must be able to fit the machine with ease and without any obstructions. It’s also important to balance the masses of each tube to avoid damage during the spinning process, particularly when using high rotor velocities.
For most applications, it’s advisable to fill the centrifuge tube three-fourths of the way. Overfilling the tube can cause it to explode during the spin or leak out of the bottom. Also, you should be careful not to exceed the maximum number of people that the tube and tow rope are rated for. You should always check your machine’s specifications to make sure that you can safely tow the desired amount of weight.
Storage
Whether you’re working in environmental labs or running molecular biology experiments, centrifuge tubes are among the most reached-for tools in your laboratory. These conical tubes are used for everything from sample storage to cell separation and many other tasks, so it’s important to choose a product that meets your needs and will withstand repeated use.
When choosing a centrifuge tube, look for options with secure caps to minimise leaks during centrifugation and storage. These closures can be secured by snaps, plug seals or screws to ensure a tight fit and prevent evaporation or contamination. Some options also feature writable surfaces or designated areas for labelling to help with identification and organisation during experimental workflows. Choosing a centrifuge tube made from a durable material that can withstand a range of conditions and temperatures is another factor to consider. Choose plastic over glass if you’re concerned about bacterial growth and if you need a product that can withstand freezing or autoclaving.
Disposable centrifuge tubes are usually created from USP class VI virgin polypropylene or high-quality polyethylene. They come in a variety of sizes, including microcentrifuge tubes that are typically used for smaller samples and can be found in a range of capacities from 15ml to 50ml. These tubes are shatterproof and often have a semi-conical shape that allows them to stand up. They are available in both sterile and non-sterile options, so it’s important to consider the nature of your samples when choosing a product. If your samples are blood-based, opt for a BD Vacutainer or similar brand of tube that is marked with a colour coded rubber bung. This helps to avoid accidental spillage of blood or other contaminants and ensures the correct sample draws each time.
Alternatively, you can opt for a cardboard centrifuge tube storage box that’s designed to hold up to 64 microcentrifuge tubes from 0.5mL to 2.0mL in an organised manner. These boxes have a transparent cover, keyed to the base and include a numbered indexing system on the back of the box for inventory control. They are also designed to fit most standard rotors and are autoclavable.