OAK Ridge Centrifuge Tubes, Plastic

Quick Answer: Oak Ridge centrifuge tubes are thick-walled plastic tubes, usually round-bottomed, with a threaded neck and screw closure, made in the Oak Ridge style for high-speed centrifuge rotors. Laboratories use them to pellet bacteria, yeast and precipitated nucleic acids and to clear debris from lysates.

What Sets the Oak Ridge Style Apart

The Oak Ridge design takes its name from Oak Ridge National Laboratory in the United States, where this tube style originated for high-speed work. Compared with the conical 15 ml and 50 ml tubes used in benchtop centrifuges, an Oak Ridge tube has a heavier wall, a rounded base and a threaded mouth that takes a sealing cap, a shape that suits the cavities of fixed-angle rotors in high-speed and superspeed machines.

Because the tube is held at an angle during the run, the pellet collects along the outer wall near the base rather than in a pointed tip. Many users draw a small mark on the outer side of each tube before loading so they know where to look for a faint or glassy pellet, such as ethanol-precipitated DNA, and they pour the supernatant off from the opposite side.

The title says only plastic, and the resin matters. Polycarbonate tubes are clear, so the pellet is easy to see, but they are weakened by alkaline solutions and many organic solvents and lose strength with repeated autoclaving. Polypropylene tubes are translucent rather than clear but resist a wider range of chemicals. Match the resin and the rated maximum g-force to your rotor before ordering.

Specifications

Applications

• Harvesting bacterial or yeast cells from broth cultures before plasmid or protein extraction
• Recovering DNA or RNA after ethanol or isopropanol precipitation
• Clarifying cell lysates by spinning down insoluble debris
• Collecting precipitates during ammonium sulfate fractionation of proteins

Using the Tubes Safely in a Rotor

• Balance opposite tubes on a scale rather than by eye, because small mass differences matter at high speed.
• Follow the rotor and tube guidance on minimum fill; partly filled plastic tubes can distort under high g-force.
• Never exceed the tube’s rated g-force, and retire any tube showing crazing, cracks or cloudiness.
• Clean with a neutral detergent; strong alkaline cleaners cause stress cracking in polycarbonate.

Why Choose LabEquip

Molecular biology, microbiology and biochemistry labs order these tubes when a benchtop centrifuge is not enough and a high-speed rotor is in use. LabEquip supplies them within its Biology Lab Products range; for low-speed spins where volume must be read, a graduated glass centrifuge tube is the alternative. Send your rotor model through the contact page so the tube can be matched to it.

Frequently Asked Questions

What is the difference between an Oak Ridge tube and a conical centrifuge tube?

An Oak Ridge tube has a rounded base, a heavier wall and a screw closure designed for fixed-angle rotors running at high g-force. A conical tube has a pointed tip that gathers a pellet neatly but is usually rated for lower speeds in swing-out or benchtop rotors.

Can Oak Ridge tubes be autoclaved?

Polypropylene tubes can generally be autoclaved. Polycarbonate tolerates it but loses strength with repeated cycles, so many labs limit the number of cycles or disinfect instead. Loosen or remove caps before autoclaving so pressure cannot build up inside.

Will the tubes fit my centrifuge rotor?

Fit depends on the diameter and depth of the rotor cavity, so compare the tube dimensions with the rotor manual. Some rotors need adapters for Oak Ridge tubes. Share the rotor model and the capacity you need when you enquire and the matching size can be confirmed.

Are polycarbonate tubes safe with phenol or chloroform?

No. Polycarbonate is attacked by phenol, chloroform and many other organic solvents, which craze or dissolve it. Polypropylene is widely used for phenol-chloroform steps, though chloroform slowly swells it, and fluoropolymer tubes are the most resistant option.

Why does my pellet sit on the side of the tube instead of the bottom?

In a fixed-angle rotor the tube is held at an angle, so particles travel a short distance outward and settle along the outer wall near the base. Marking the outer side of each tube before the run shows where the pellet will form.

How do I spin a hazardous sample safely?

Tighten the screw cap fully and check the sealing surface for nicks first. Load and unload infectious material inside a biosafety cabinet and use a rotor with a sealed lid where available, since a leaking tube can release aerosols.

Last Updated: September 2026