Choose the right centrifuge tube for your application
Centrifuge tubes can help you organize samples, avoid contamination, and even make work more fun!
Sure, choosing your next centrifuge tubes may not seem like the biggest decision you’ll be making today. But your choice can actually have a big impact on your work!
The right centrifuge tubes can make your workflow and work life more effective.
Centrifuge tubes can:
- Simplify sample identification & organization
- Improve sealing security
- Help avoid sample contamination
- And (don't look it up or anything) studies show they can even make work more fun.
Plus you want to consider elements like size, graduation, centrifugation speeds, materials, and more when you make your next purchase. This article looks at factors to consider to order the right centrifuge tubes for every user.
First thing’s first. What are centrifuge tubes?
Centrifuge tubes are used to contain liquid samples during the centrifugation process, which separates the sample by rotating rapidly around a fixed axis. Centrifuge tubes must be able to withstand centrifugal force created during use.
Or, in english, centrifuge tubes hold liquids and spin really, really fast in a centrifuge.
Most centrifuge tubes have conical bottoms, collecting solids or heavier parts of the sample after centrifugation.
Who uses centrifuge tubes?
With their simple design, centrifuge tubes are used in a plethora of applications. Scientists, researchers and professionals across a range of industries rely on centrifugation to get their work done.
- Scientists in chemical labs need to consider the chemical compatibility of their samples and their conical tube. Polypropylene tubes might be a good option because of its resistance to most organic solvents (including acidic samples)
- Scientists in pharma need centrifuge tubes with greater granulated markings, with a cap easily accessible by syringe or needle.
- Scientists in environmental labs may choose a snap cap lid for easy sample collection and storage. Or they may prefer a screw cap lid for samples where evaporation or leaks during centrifugation can affect research outcomes.
In fact, researchers have been using variations of this conical tube since the 1930s! Today, they’re a staple in laboratories around the world. Centrifuge tubes are some of the most reached-for tools in labs for a reason. They’re constant. Ever present. Like a fork in your kitchen. From sample storage to cell separation, and countless tasks in between, you reach for a centrifuge tube.
Choosing the right centrifuge tube for your application
It’s not a one size fits all solution when it comes to centrifuge tubes and your application. Some questions every user should ask themselves includes:
- What are you doing with your samples? Refrigerating or freezing them? Incubating them?
- What RPM or G Force are you centrifuging your samples at?
- Are you working with light sensitive samples?
- How concerned are you about sample contamination?
- How important is identification and storage for your application?
- What level of accuracy do you need?
Centrifuge tubes come in a variety of volume capacities, materials, configurations, RCF ratings, and closure types (screw cap, snap cap). They may be sterile or non-sterile. Their graduations vary, so you can measure value to different degrees of precision.
Centrifuge tubes are available in various styles, sizes, and materials. Some things to think about when ordering yours includes:
- Capacity: The most common sizes are the 15 mL and 50 mL centrifuge tube, and 1 mL to 2 mL microcentrifuge tubes, although sizing can range from a 0.1 mL tube to 100 mL conical tube, or more.
- Sealing: Screw caps are great for extra security. Snap caps are simple and easy to open and close one-handed.
- Graduations:Centrifuge tubes will have different graduations, affecting the level of precision you can measure. The snap cap centrifuge tubes from Globe Scientific come with dual graduation scales of 0.2mL and 0.5mL, for the most precise measurement.
- Shape: Conical- or round-bottomed? Some conical centrifuge tubes are skirted and free-standing (which can help with storage space and preventing spills).
- Material: Consider your samples and material compatibility when selecting your centrifuge tube. Common tubing materials include polypropylene (PP), polyallomer (PA), polycarbonate (PC), and polyethylene terephthalate (PET). Both PP and PA are opaque, and offer good chemical resistance. PC and PET are clear, and tend to offer poorer chemical resistance, so factor in your samples when making your selection.
- Sterility:Both sterile or nonsterile options are available, depending on your application. If you’re collecting soil samples, you may not require a Class 10,000 cleanroom-certified centrifuge tube. However, if you’re in forensics you may need a tube centrified free of Human DNA.
- Color:Color: Multicolored centrifuge tubes can make identifying and storing samples significantly easier. AND significantly more fun!
If organization and sample identification is your jam...
How do you currently track your groups of samples before and after spinning up the centrifuge? The easiest way to organize and identify your samples? Use multicolored centrifuge tubes.
If precision matters to you more than most...
Constructed with a conical bottom, centrifuge tubes increase accuracy of pipetting and reduce sample waste by driving the sample down to a focused point.
Graduated volumes up the centrifuge tube make it easy to identify volume and measure sample amounts. The graduated volume you choose will depend on your application and the level of precision you need.
The snap cap is great for one-handed opening and closing, easily accessed by syringe or needle, with dual graduation scales of 0.2mL and 0.5mL for more precise measurement AND seven color options available to identify and organize samples
The screw cap is perfect for extra secure sealing, measures in 0.5mL increments, and is available in either sterile or non-sterile options.
How fast does your centrifuge spin?
Centrifuge tubes must also be able to withstand the centrifugal pressure created during their use, and their specifications may indicate the maximum centrifugal force (and speeds) at which they can be safely used.
The speed capacities of tubes vary greatly, so it’s important to choose a tube that can withstand the speed of your centrifugation process. When looking at speeds, it is best to look at RCF, rather than RPM. RCF factors in the gravitational force being applied (while RPM only takes into account the rotors spinning speed).
Pricing varies depending on the max RCF a tube can handle. If you’re not dealing with high speeds, you can choose a tube with a lower RCF to save on costs. And if you’re a volume user, savings can add up substantially over time.
Sealing your sample inside the centrifuge tube
- Snap cap: If your hands are often full, choose a snap cap centrifuge tube. These are great for one-handed opening and closing,
easily accessed by a syringe or needle, and have dual graduation scales of 0.2mL and 0.5mL for the most precise measurement.
They’re also available in 7 colors for easy storage and identification.
See snap cap centrifuge tubes here
- Screw cap: If you’re looking for extra secure sealing, invest in a screw cap.
Measuring in 0.5mL increments, the Globe Scientific screw cap centrifuge tube is available in both sterile and non-sterile options.
See screw cap centrifuge tubes here
Keeping your pipette shaft clean
If sample contamination is something you worry about in your application, choose a centrifuge tube that helps limit this as much as possible.
Globe Scientific macrocentrifuge tubes reduce pipette shaft contamination. There’s no need to insert the pipettor barrel into the tube to retrieve samples with this model.
Your best bet from Globe Scientific
Let’s get to the fun stuff - colors!
How to clean centrifuge tubes?
Wash your centrifuge tubes with a mild laboratory detergent solution, diluted 10 to 1 with warm water. Always rinse and air dry your tubes after use.
A couple of other best practices include:
- Always inspecting tubes for damage or cracks before use
- Don’t soak tubes or bottles in hot water or detergent solution for longer than 10 minutes
- Never put your centrifuge tubes in a dishwasher
- Carefully filling and sealing tubes, as centrifugal force may cause improperly filled or sealed centrifuge tubes to collapse
- Be sure that plastic labware is thawed to at least 2°C prior to centrifugation.
- Make sure all tubes are completely dry before storing them.
- Store your centrifuge tubes in their containers, in a cool, dry location away from chemical fumes, ozone, and ultraviolet light.
When placing centrifuge tubes in the centrifuge, what are the best practices?
It’s important to balance your centrifuge tubes. If you place two test tubes in your centrifuge, with one 0.5 mL sample and one 1 mL sample, your results will not be precise.
Once your tubes are at equal volume, the next step is to balance them in your centrifuge. Place the tube samples directly opposite of each other.
If you only have one sample, there’s an easy solution! Take a second tube of the same size, fill it with the same amount of water as your other sample, and you’re ready to go.
Know what you’re looking for?
With all this in mind, you’re well on your way to finding the centrifuge tubes that will make your life easier!
Still not sure what you’re looking for?
Get in touch, and we’ll point you in the right direction.