In this section, you'll attach a pipette to your OT-2.

Your OT-2 has two pipette mounts. Each pipette mount can hold one Opentrons pipette. The pipette screws into the mount, and the OT-2 controls it electrically through a cable.

Pictured: the left mount, with no pipette attached (left) and with a P300 Single-Channel GEN2 attached (right). The right mount is raised and hidden from view.

Before starting

Determine if you have a GEN1 or GEN2 pipette

Some of these steps change depending on whether your pipette is GEN1 or GEN2. If you're not sure, see: Do I have a GEN1 pipette or a GEN2 pipette?

Gather required tools

  • You'll need a 2.5 mm hex driver, included with your OT-2.
  • If you're attaching an 8-Channel GEN2 pipette, you'll also need your calibration block. The calibration block came in its own box, shipped along with your 8-Channel GEN2 pipette.

Prepare an older OT-2 for GEN2 pipettes

If you're attaching a GEN2 pipette, and you have an older OT-2, you might need to make a hardware adjustment.

Check when your OT-2 was manufactured. If it was before 2019-09-05, follow the steps in Preparing older OT-2s for GEN2 pipettes before continuing here.

Step 1: Lower the pipette mount for access

In the Opentrons App, go to the Pipettes & Modules page for your OT-2.

Select Attach for the mount that you want your pipette to go on. The gantry will move towards the front window, and the mount will lower.

Step 2: Select which pipette you'll attach

From the dropdown menu in the Opentrons App, select the model of pipette that you want to attach.

If you have both a GEN1 pipette and a GEN2 pipette, attach the GEN1 first. Otherwise, space limitations might make it difficult to squeeze into place.

Step 3: Align the pipette to the mount

Start with the pipette behind the mount. Slide the pipette towards you, keeping it vertical. The connector on the pipette should match up with the connector on the mount.

If you have a GEN2 pipette, you'll know it's aligned properly if it feels like the pipette is hanging off a hidden ledge.

Hold the pipette in place.

Tip: If you're having trouble, it can help to get low, so you can view the pipette and mount from below. Otherwise, your view might be blocked by the pipette mount cover.

Step 4: Loosely screw the pipette into the mount

A total of three 2.5 mm hex screws will secure your pipette to its mount. There are two top screws and one bottom screw.

The two top screws are permanently embedded in the transparent plastic at the top of the mount.

The single bottom screw needs to be inserted separately. Several bottom screws came with your pipette, packed in a small bag.

Screw in all three screws, but leave them slightly loose.

Top screws:

Bottom screw:

Step 5: If you're attaching an 8-Channel pipette, level it

8-Channel pipettes are especially sensitive to tilt. If you're attaching one, some extra steps are needed to make sure it's attached perfectly straight. (To learn more, see Leveling 8-Channel pipettes.)

If you're attaching a Single-Channel pipette, skip ahead to step 6.

Level a GEN1 8-Channel pipette

  1. Use your hand to gently and slowly pull the pipette all the way down to the OT-2's deck.
  2. Wiggle the pipette so that all 8 of its nozzles touch the deck at the same time.
  3. While holding the pipette down, tighten the 3 screws.

Level a GEN2 8-Channel pipette

You'll need to use this leveling block shipped with your pipette.

The Opentrons App will show you a video with instructions for using it.

What if I can't level the pipette completely?

You might have trouble leveling the pipette perfectly. There might not be enough wiggle room to get all 8 channels to touch the surface at once. Or, the pipette might spring back a little bit when you tighten the 3 screws.

If the difference between channels is less than 0.15 mm, it's level enough. (0.15 mm is the thickness of between one and two sheets of typical printer paper.) If it's more than 0.15 mm, and you're unable to correct it, your OT-2 might need more adjustment. Contact Opentrons Support for help.

Step 6: Tighten the three screws

Tighten the 3 pipette screws.

When tightened, all three screws should feel firm. If it feels like a screw is still spinning freely, it's misaligned. You might need to go back to step 4 and wiggle the pipette to get all 3 screws to thread into their holes.

Step 6: Connect the pipette cable

You're almost done! After screwing in the pipette, you'll need to plug it in. Your OT-2 will control the pipette through a white ribbon cable.

Find the white connector tab and press it in, towards the pipette, as far as you can. You should feel it plug in to the pipette.

Step 7: Check the pipette connection

We need to make sure that the OT-2 can communicate with the pipette over the cable you just plugged in.

In the Opentrons App, select Have robot check connection. Your OT-2 will test the connection automatically.

If all goes well, you'll see a green checkmark. Select Exit pipette setup to move on.

Not getting a green checkmark?

If you see an "Unable to detect pipette" error message, see: Troubleshooting pipette connection problems.


You've attached a pipette to your OT-2! Select Exit pipette setup to move on. You can come back to this process at any time to add, remove, or swap pipettes.

If you have a second pipette, you'll need to repeat this process for that one, too. 

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