Tubes & Tube Racks

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What are they and why do we use them? What types are there?

Plastic tubes are a ubiquitous and necessary part of life in micro/molecular/synthetic biology. Learning all the types and nicknames can take a while, but you’ll pick up the lingo before too long. We use plastic tubes to sterilely contain a liquid from the external environment. The main types used in a lab are;

  1. 0.2 ml PCR Tubes - Thin walled tubes for PCR. The thin plastic allows for rapid heat transferral. Can also be centrifuged. Often come as a tube-rack, with 8-12 bound together (see image above).

  2. 0.5 ml Microcentrifuge tubes aka. Mini-eppi tubes - Used by some centrifuges. Nest very nicely inside 1.5 ml eppendorf tubes for protocols such as the Cotton Wool Gel Purification Protocol.

  3. 1.5 ml Microcentrifuge tubes aka. Eppi/eppy tubes, Eppendorf tube -

  4. 15 ml Centrifuge Tubes aka. 15 ml Falcon Tube -

  5. 50 ml Centrifuge Tubes aka. 50 ml Falcon Tube -

Names like Falcon/Eppy are simply brand names that have stuck and entered the standard lexicon, like Jacuzzi Hot Tubs or Hoover Vacuum Cleaners.

Tube Racks are used for holding tubes. They come in all shapes and sizes, all that matters is that the size of the holes matches the size of your tubes. This will prevent unwanted spillage.

When do you use?

All the time. Before starting a protocol, consider the maximum volumes that you will be encountering and choose appropriate tubes. Most protocols will include specific tube sizes.

Sometimes your tube selection will be gated by what centrifuges you have available. If you only have a mini centrifuge, you may need to split the contents of a 15 ml falcon tube amongst 10 x 1.5 ml microcentrifuge tubes.

How do you use?

Autoclave tubes in a glass beaker covered in aluminium foil. Lift the foil to remove tubes as required and then replace. For larger tubes, use autoclave bags and keep them in the bag. Do not reuse plastic tubes, most will need to be sent to be burned or destroyed as biological waste.

According to Sterile technique, only pop the tube cap when required for sterile transfer. Otherwise keep the cap of the tube closed at all times.