Eppendorf tube label template

The name and the size

Eppendorf SE makes microcentrifuge tubes, and the name has been used generically for the whole class for decades — much as “Falcon tube” stands in for any conical centrifuge tube. For labelling purposes the distinction does not matter: a 1.5 mL tube from any manufacturer has a barrel of roughly 8.5 mm, and 25.4 × 12.7 mm wraps it.

Where it does matter is when someone hands you a 2 mL tube and calls it the same thing. A 2 mL microcentrifuge tube is a little wider and noticeably taller; the same 25.4 mm label wraps it comfortably, with more room to spare, so a label sized for 1.5 mL is the safe default for both.

Microcentrifuge tube sizes and the labels that fit

How much text fits

What the label has to survive on this tube

The heat block

Denaturation at 95 °C for ten minutes is routine, and a direct thermal label will come out uniformly black. A toner or resin print on a synthetic face is unaffected. If tubes go into a block regularly, that alone decides the printing method.

The centrifuge rotor

At 21,000 × g the label carries only its own weight, but a lifted edge catches the rotor pocket as the tube goes in and out. This is why a wrap that leaves a small gap outlasts one sized to butt or overlap.

The lid hinge

A Safe-Lock style lid folds back against the barrel. A label wrapped too high sits under the open lid and gets creased every time the tube is opened, and a creased label lifts.

Repeated freeze–thaw

A −20 °C aliquot that comes out weekly is cycled far more than one frozen once. Condensation on each thaw runs into the label edge and freezes there on the way back, which is what eventually levers the label off.

Autoclaving, if it happens before use

121 °C wet heat destroys most label adhesives outright. Label after autoclaving, never before.

Where to put it on the tube

The barrel of a 1.5 mL tube is conical below the shoulder, so only the top few millimetres are close enough to cylindrical for a rectangular label to lie flat. Applied lower, the label's top edge lifts away from the wall — and that is the edge a rotor pocket meets first.

Wrap the label with its top edge just below the lid seal, not tucked under it. Leaving a millimetre of clearance keeps the lid closing cleanly and keeps the label out of the hinge crease.

The other option is to skip the barrel and use the cap, which is read from above in a rack and never touches the rotor. The cost is traceability: a cap can be swapped between tubes, so a cap label identifies the cap rather than the sample. Use it for a working set, not for anything that has to be defensible later.