Centrifuges are essential tools used for everything from separating blood components to purifying proteins to preparing cell cultures. Whether you're a researcher or a purchasing agent, buying a used centrifuge can be a smart way to save money while acquiring reliable equipment. However, there are some factors to take into account before you make the investment so you can get equipment that performs as expected.
Centrifuge Functioning and Maintenance
A centrifuge is a laboratory machine used to separate components based on their density. The mechanism involves a rotor, which holds sample containers and spins them around a central axis. The speed is measured in revolutions per minute (RPM).
Basic centrifuge maintenance includes a few simple steps:
- Daily cleaning: After each use, wipe down the rotor, chamber and seals with a soft cloth and a noncorrosive cleaning solution. This step prevents residue buildup and corrosion.
- Inspect rotors regularly: Check for cracks, discoloration or signs of stress. Follow the manufacturer's guidelines for rotor life span and replacement.
- Balance the load: Always load the centrifuge symmetrically to prevent issues.
To maximize your centrifuge's life span, you should:
- Follow the manufacturer's guidelines for using the machine.
- Upgrade the centrifuge when necessary.
- Invest in a high-quality centrifuge, even when purchased used.
8 Tips for Buying a Used Centrifuge
Ready to start shopping for your equipment? Here are some tips for purchasing a used centrifuge:
1. Consider Your Application Needs
Pinpoint how the machine will be used by identifying its main purpose. Choosing a centrifuge without a clear understanding of your application may lead to wasted resources.
Start by writing down your most common tasks, and then match these requirements to specific centrifuge features. These details will help determine the type, size and speed of the centrifuge you'll need.
2. Inspect the Condition and Check the Warranty
Used centrifuges may have wear or damage. Centrifuge components endure immense forces, leading to fatigue or damage that may compromise performance. Look for signs of rust, cracks or discoloration. If the centrifuge has been idle for years, components may have deteriorated, so don't hesitate to run a test spin if the seller allows it. A trustworthy seller will be upfront about the centrifuge's condition and only supply working machines.
A comprehensive warranty provides peace of mind. If the centrifuge fails shortly after purchase, a warranty allows you to seek repairs or a replacement without incurring extra costs. Ask the seller about warranty terms or return policies. Even a short-term warranty can make a big difference.
3. Check the Manufacturing Date
Some manufacturers encode a unit's manufacture date in its serial number. Beckman Coulter centrifuges, for instance, contain the last two digits of the year they were manufactured after the first three alphabetic characters. For example, a centrifuge with the serial number ALR06D12 was manufactured in 2006. Not sure how your centrifuge's manufacturer encodes dates? Shoot a message over to their technical support team. Here are a few links to the support lines of other centrifuge manufacturers:
4. Request Product Documentation
Without product documentation, you may miss crucial details about maintenance schedules, proper usage or safety precautions. Plus, detailed manuals typically include troubleshooting guides that save time. If the seller doesn't provide documentation, check the manufacturer's website or contact their support team — some companies offer digital copies of user manuals.
If you can't find the manual in the above-mentioned places, there are a few other sources you could try:
- LabWrench: LabWrench is a forum dedicated to sharing news, documentation, and other information on lab equipment. There's always a chance your centrifuge's manual could be found on LabWrench.
- MedWrench: Despite their similar names, MedWrench is completely unrelated to LabWrench. But its premise is the same: it's a product-focused forum for medical equipment, including certain centrifuges. If your centrifuge is approved for diagnostic use, you may find its documentation on MedWrench.
Finally, if all else fails, you could always just Google it! Lots of universities and other sources have manuals scattered around the web. However, make sure you only download files from a website you trust. We recommend only visiting the sites of manufacturers or educational institutions — sites ending in .edu — to be safe.
5. Inspect Rotor Compatibility
Determining if a rotor will work with your centrifuge is as easy as checking the centrifuge's operation manual. Don't have the manual? More on that below. Most manuals include a table detailing every compatible rotor. Should you not find a particular rotor in that table, it's safe to assume that the rotor is not compatible.
However, New Life Scientific has created a simpler way to find compatible rotors. Visit our Rotor Compatibility Chart and use it to answer your compatibility questions. With a simple search, you can find which rotors are compatible with your target centrifuge or vice-versa.
If you can't find a manual or your centrifuge's data in our compatibility chart, you may still be able to find this information by googling the rotor's model number. Many resellers specify the centrifuges compatible with each rotor they list for sale. You can also browse our current inventory of rotors. If you don't find one that suits your needs, feel free to contact us because we can source one for you.
Much like rotors, you can check the centrifuge's manual to see which adapters its swing-bucket rotors accept. But if that information isn't in the manual, you can usually find the information by Googling the adapter's model number and viewing the listings for those adapters. Those listings often detail which rotors the adapter fits. Browse our current inventory of adapters. If you don't find any compatible with your rotor, feel free to contact us as we may be able to source some for you.
6. Verify Calibration and Safety Features
A poorly calibrated centrifuge can produce inconsistent results and jeopardize research or patient outcomes. Confirm calibration with the seller. Ask for documentation showing the last calibration date and who performed it. If the centrifuge hasn't been calibrated recently, factor in the cost of professional calibration.
A centrifuge spinning at high speed generates immense forces, which can make it a potential hazard if something goes wrong. Review the centrifuge's safety features carefully and check that they function correctly. Also, double-check that the control systems are responsive and reliable.
7. Check the Relative Centrifugal Force
When shopping for a new centrifuge, you should focus more on its g-force capabilities than its speed capabilities. G-force, or relative centrifugal force (RCF), is the key to centrifugation. It measures the gravitational force applied to samples as they spin. Speed, along with the radius of the rotor, are merely the factors used to calculate g-force.
Thus, two centrifuges set to spin at the exact same RPM but with different rotors will generate two different amounts of g-force, and their respective samples won't separate to the same degree. Selecting a centrifuge based only on its speed can be misleading. By shopping with your g-force requirements in mind, you can rest assured that you'll find a centrifuge and rotor suitable for your work.
If you know what volume and RCF you need, you can use our Benchtop Centrifuge Selection Guide to find the perfect centrifuge model for your laboratory's needs.
8. Look at Capacity, Size and Space
If you'll be processing a high volume of samples or need flexibility in tube sizes, verify the maximum volume a centrifuge can handle per cycle. A centrifuge that's too small for your workload can lead to inefficiencies and additional cycles, while an oversized machine might take up space. Also, a large centrifuge can create logistical challenges, while a compact model might lack the necessary capacity.
Measure your lab space, including ventilation clearance, before making a purchase.
Contact New Life Scientific for Used Centrifuges
New Life Scientific provides high-quality used centrifuges for your needs and budget. Every centrifuge we sell is thoroughly tested by our skilled technicians, ensuring it can efficiently perform to your satisfaction. Our centrifuges come with a comprehensive warranty, and our fast response time and after-sale support means you'll receive assistance when you need it. Browse our selection and contact us today to get started!
