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

1-ch. 50 µL8-ch. 50 µL1-ch. 1000 µL8-ch. 1000 µL96-ch. 1000 µL

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

1-ch. 50 µL8-ch. 50 µL1-ch. 1000 µL8-ch. 1000 µL96-ch. 1000 µL

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

1-ch. 50 µL8-ch. 50 µL1-ch. 1000 µL8-ch. 1000 µL96-ch. 1000 µL

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

1-ch. 50 µLFlex P50 8-channel1-ch. 1000 µL8-ch. 1000 µL96-ch. 1000 µL

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

1-ch. 50 µL8-ch. 50 µL1-ch. 1000 µL8-ch. 1000 µL96-ch. 1000 µL

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

1-ch. 50 µL8-ch. 50 µL1-ch. 1000 µL8-ch. 1000 µL96-ch. 1000 µL

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

1-ch. 50 µL8-ch. 50 µL1-ch. 1000 µL8-ch. 1000 µL96-ch. 1000 µL

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

1-ch. 50 µL8-ch. 50 µL1-ch. 1000 µL8-ch. 1000 µL96-ch. 1000 µL

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

1-ch. 50 µL8-ch. 50 µL1-ch. 1000 µL8-ch. 1000 µL96-ch. 1000 µL

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