Liquid Class Definitions

A liquid class definition specifies nearly all transfer behavior a Flex pipette will perform during a InstrumentContext.transfer_with_liquid_class(), InstrumentContext.distribute_with_liquid_class(), or InstrumentContext.consolidate_with_liquid_class(). Properties, like aspirate flow rate, submerge speed, or dispense position, are required in every liquid class definition.

This section details specific changes to transfer behavior for each Opentrons-verified liquid class. The transfer steps are listed in the order the robot performs them. Advanced settings like mix, pre-wet tip, touch tip, and blowout are automatically disabled in Opentrons-verified liquid class definitions.

Note

You can customize a liquid class definition for your workflow, either by customizing individual properties of an Opentrons-verified liquid class definition or by creating your own definition from scratch.

For more information, see Customizing Liquid Classes.

To use the tables below, select your liquid class: Aqueous, Viscous, or Volatile. Then, click different tabs to view your pipette and tip combination.

In a liquid class transfer, flow rates and air gap or push out volumes vary based on the pipette and tip combination used in your protocol. Let’s say you use a Flex P1000 1-channel pipette and Flex 200 µL tips to aspirate a volatile liquid. The transfer volume specifies the flow rate:

  • 7 µL/sec to aspirate 5 µL

  • 50 µL/sec to aspirate 50 µL

  • 200 µL/sec to aspirate 200 µL

When your aspirate volume falls in between, like 100 µL, a linear interpolation automatically determines the flow rate.

Aqueous

The Opentrons-verified aqueous liquid class is based on deionized water.

Aspirate

Behavior

50 µL

Submerge speed

100 mm/sec

Aspirate flow rate by volume

  • 1 µL: 35 µL/sec

  • 10 µL: 24 µL/sec

  • 50 µL: 35 µL/sec

Correction by volume

Delay after aspirating

0.2 sec

Retract speed

50 mm/sec

Delay after retracting

Air gap by volume

  • 1–49.9 µL: 0.1 µL

  • 50 µL: 0 µL

Dispense

Behavior

50 µL

Submerge speed

100 mm/sec

Dispense flow rate

50 µL/sec

Correction by volume

Delay after dispensing

0.2 sec

Retract speed

50 mm/sec

Delay after retracting

Push out by volume

  • 1–4.9 µL: 7 µL

  • 5-50 µL: 2 µL

Air gap by volume

  • 1–49.9 µL: 0.1 µL

  • 50 µL: 0 µL

Multi-dispense

Behavior

50 µL

Submerge speed

100 mm/sec

Dispense flow rate

50 µL/sec

Correction by volume

Conditioning by volume

  • 1–45 µL: 5 µL

  • 50 µL: 0 µL

Disposal by volume

  • 1–45 µL: 5 µL

  • 50 µL: 0 µL

Delay after dispensing

Retract speed

50 mm/sec

Delay after retracting

0.2 sec

Air gap by volume

  • 1–49.9 µL: 0.1 µL

  • 50 µL: 0 µL

Viscous

The Opentrons-verified viscous liquid class is based on 50% glycerol.

Aspirate

Behavior

50 µL

Submerge speed

4 mm/sec

Aspirate flow rate by volume

  • 1 µL: 7 µL/sec

  • 10 µL: 10 µL/sec

  • 50 µL: 50 µL/sec

Correction by volume

  • 1 µL: -0.5 µL

  • 10–50 µL: -0.2 µL

Delay after aspirating

1 sec

Retract speed

4 mm/sec

Delay after retracting

Air gap by volume

0 µL

Dispense

Behavior

50 µL

Submerge speed

4 mm/sec

Dispense flow rate

25 µL/sec

Correction by volume

  • 1 µL: -0.5 µL

  • 10–50 µL: -0.2 µL

Delay after dispensing

0.5 sec

Retract speed

4 mm/sec

Delay after retracting

Push out by volume

  • 1–4.9 µL: 11.7 µL

  • 5-50 µL: 3.9 µL

Air gap

0 µL

Multi-dispense

Behavior

50 µL

Submerge speed

4 mm/sec

Dispense flow rate

25 µL/sec

Correction by volume

  • 1 µL: -0.5 µL

  • 10–50 µL: -0.2 µL

Conditioning by volume

  • 1–40 µL: 5 µL

  • 45–50 µL: 0 µL

Disposal by volume

  • 1–40 µL: 5 µL

  • 45–50 µL: 0 µL

Delay after dispensing

0.5 sec

Retract speed

4 mm/sec

Delay after retracting

Air gap

0 µL

Volatile

The Opentrons-verified volatile liquid class is based on 80% ethanol.

Aspirate

Behavior

50 µL

Submerge speed

100 mm/sec

Aspirate flow rate by volume

  • 1 µL: 7 µL/sec

  • 10 µL: 10 µL/sec

  • 50 µL: 30 µL/sec

Correction by volume

  • 1 µL: -1.6 µL

  • 10 µL: -1.1 µL

  • 50 µL: -3 µL

Delay after aspirating

0.2 sec

Retract speed

100 mm/sec

Delay after retracting

0.5 sec

Air gap by volume

  • 1–45 µL: 5 µL

  • 50 µL: 0 µL

Dispense

Behavior

50 µL

Submerge speed

100 mm/sec

Dispense flow rate

30 µL/sec

Correction by volume

  • 1 µL: -1.6 µL

  • 10 µL: -1.1 µL

  • 50 µL: -3.0 µL

Delay after dispensing

0.2 sec

Retract speed

100 mm/sec

Delay after retracting

0.5 sec

Push out by volume

1.0µL

Air gap by volume

  • 1–45 µL: 5 µL

  • 50 µL: 0 µL

Multi-dispense

Behavior

50 µL

Submerge speed

100 mm/sec

Dispense flow rate

30 µL/sec

Correction by volume

  • 1 µL: -1.6 µL

  • 10 µL: -1.1 µL

  • 50 µL: -3.0 µL

Conditioning by volume

  • 1–40 µL: 5 µL

  • 45–50 µL: 0 µL

Disposal by volume

  • 1–40 µL: 5 µL

  • 45–50 µL: 0 µL

Delay after dispensing

0.2 sec

Retract speed

100 mm/sec

Delay after retracting

0.5 sec

Air gap by volume

  • 1–45 µL: 5 µL

  • 50 µL: 0 µL