When a centrifuge tube runs out, it is tempting to reorder by capacity alone. Two tubes of the same nominal volume can differ in shape, cap design and the force they are rated to withstand. Start with your rotor and method, then use those details to compare tubes and request a quote.
Confirm the fit with your rotor or adapter
Record the centrifuge model, the rotor model and any adapter in use. Check the equipment documentation for compatible tube dimensions, bottom shape and closure. A cap can affect whether the assembled tube fits the rotor, so verify the tube and cap as a combination.
If you are replacing an existing tube, include its catalogue number in the enquiry. This gives the supplier a reference to check if you need the same item or want to assess an equivalent.
Check the required relative centrifugal force
Revolutions per minute (RPM) describes how fast the rotor spins. Relative centrifugal force (RCF), typically expressed as × g, depends on both spin speed and rotor radius. Two different rotors can therefore produce different forces at the same RPM.
Use the RCF specified by your method to check the tube’s rating. If the method gives RPM only, use the equipment manufacturer’s guidance to determine the corresponding RCF for the rotor. Check the conditions attached to the tube rating, including any required support, fill limits or temperature restrictions. Confirm that the tube, rotor and adapter are all suitable for the intended run.
Choose the working volume, material and closure
Check the amount of liquid you actually need to spin, including any reagents added during preparation. Compare this with the tube’s permitted fill range for the application. If your method requires recovering a pellet, check whether a conical bottom suits the recovery step and fits the rotor.
Review the tube and cap materials against the sample, reagents and operating temperature. If the method calls for sterile tubes or a specific certification, put that requirement on the purchase request and verify it on the product documentation.
What to include when requesting a quote
- Centrifuge and rotor models, plus the adapter if used
- Current tube part number or required tube dimensions
- Sample volume, tube capacity, bottom shape and closure
- Required RCF, operating temperature and sample or reagent type
- Sterility or certification requirements and order quantity
B&M Scientific lists centrifuges and centrifuge tubes in its catalogue. Send your equipment details and tube requirements to customercare@bmscientific.co.za to request a quote and confirm available options.
