Before you run your protocol, the Opentrons App will prompt you to do one more kind of calibration: labware calibration, which accounts for dimensional and positioning variation in tip racks and labware.
(To learn more, check out How calibration works on the OT-2.)
Step 1: Begin
From the Protocol tab, select the Calibrate tab or the Proceed to calibrate button:
Step 2: Calibrate tip lengths
Depending on what tips your protocol uses, the Opentrons App might prompt you to do some more tip length calibrations.
Follow the Opentrons App's instructions. You'll follow the same procedure as in Get started: Calibrate tip length and pipette offset.
Step 3: Calibrate labware
Follow the Opentrons App's instructions to calibrate your labware, including your tip racks themselves. The Opentrons App will guide you through:
Placing your labware in their proper slots on the OT-2's deck.
Centering a pipette's tip over their wells.
Caution: Make sure that the labware you place exactly matches what the protocol specifies! For example, don't substitute one 96 well plate for another. Otherwise, the OT-2 might not be able to correctly position the pipette within the labware's wells. If you're not sure, you can look the labware up in our Labware Library, where you'll find its dimensions and catalog numbers.
Caution: During labware calibration, you shouldn't have to adjust the pipette by more than a few millimeters. Labware calibration is meant for small adjustments. If centering the pipette requires a bigger adjustment, you might not be using the right labware.
After calibrating all labware, select Return tip and proceed to run.