Basic Pipetting

Aspirating and dispensing with the Tecan Freedom EVO MCA96 head.

The Freedom EVO is supported in liquid handling SDK versions >=0.35.0.

In this guide a deck with a plate, tips, and a trough is created. Tips are picked up to aspirate liquid from the trough and dispense into a plate. Both direct keyword arguments and parameter sets are demonstrated.

Prerequisites

A switched on Tecan Freedom EVO device with a Multi-Channel Arm
A tip carrier with EVO tips, a plate carrier with a destination plate, and a trough
A running Tecan Freedom EVO connector
Basic understanding of the liquid handler class (See Deck & Carriers)
Basic understanding of tip handling (See Tip Handling)

Power On the System

from unitelabs.sdk import AsyncApiClient
from unitelabs.labware import Vector
from unitelabs.liquid_handling.tecan import TecanFreedomEvo, TecanFreedomEvoConfiguration

client = AsyncApiClient()

evo = TecanFreedomEvo(
    name="Tecan Freedom EVO",
    client=client,
    configuration=TecanFreedomEvoConfiguration(mca_discard_location=Vector(x=1000, y=100, z=100)),
)
await evo.configure()
await evo.initialize()
await evo.activate()

Arrange the Deck

from unitelabs.labware.liquids import PredefinedLiquids
from unitelabs.labware.plates import Standard96Plate
from unitelabs.labware.tecan import EvoTipBox_MCA_DiTi_200, EvoTip_MCA_DiTi_200, MP_3Pos_flat, MP_4Pos_flat
from unitelabs.labware.troughs import StandardTrough

tip_carrier = MP_4Pos_flat()
tip_box = EvoTipBox_MCA_DiTi_200(identifier="TipBox_200uL")
tip_box.fill(EvoTip_MCA_DiTi_200)
tip_carrier[0] = tip_box
evo.deck.add(tip_carrier, track=1)

plate_carrier = MP_3Pos_flat()
source_trough = StandardTrough(identifier="SourceTrough_Water")
source_trough.container.add_liquid(PredefinedLiquids.WATER, 50_000.0)
dest_plate = Standard96Plate(identifier="DestinationPlate_96Well")

plate_carrier[0] = source_trough
plate_carrier[1] = dest_plate
evo.deck.add(plate_carrier, track=8)

Aspirate

Pick up tips first, then aspirate from the trough.

await evo.mca.pick_up_tips_from(rack=tip_box)

await evo.mca.aspirate(
    source=source_trough,
    volume=100,
)

Dispense

Dispense the aspirated volume into the destination plate.

await evo.mca.dispense(
    target=dest_plate,
    volume=100,
)

Using Parameter Sets

For more control, use MCAAspirateParameterSet/MCADispenseParameterSet instead of keyword arguments. A device-independent AspirateParameterSet/DispenseParameterSet is also accepted and adopted onto the EVO-specific class.

from unitelabs.liquid_handling.tecan.modules import MCAAspirateParameterSet, MCADispenseParameterSet
from unitelabs.liquid_handling.modules import PipetteMode

aspirate_params = MCAAspirateParameterSet(volume=100)
await evo.mca.aspirate(source_trough, aspirate_params)

dispense_params = MCADispenseParameterSet(
    volume=100,
    pipette_mode=PipetteMode.BOTTOM,
    liquid_offset=3.0,
)
await evo.mca.dispense(dest_plate, dispense_params)

Using the parameter set form is mutually exclusive with keyword arguments. An aspirate or dispense receiving a parameter set will drop any keyword arguments and use only the information from the parameter set.

Liquid Classes

Pass a liquid class to calibrate the plunger physics for the liquid being handled — see Liquid Classes for details.

from unitelabs.labware.tecan import EvoLiquidClass

await evo.mca.aspirate(source_trough, volume=100, liquid_class=EvoLiquidClass())

Mixing

Mix in place before an aspirate, or after a dispense, by setting mix_cycles (and optionally mix_volume/mix_liquid_offset).

await evo.mca.aspirate(
    source=source_trough,
    volume=100,
    mix_cycles=3,
    mix_volume=50,
)

Touch-Side Dispense

Setting touch_side=True moves the tips against the well wall after dispensing, deriving the distance from the destination's geometry. This is only supported for plate/well targets, not troughs.

from unitelabs.liquid_handling.tecan import TouchTipDirection

await evo.mca.dispense(
    target=dest_plate,
    volume=100,
    touch_side=True,
    touch_side_direction=TouchTipDirection.EAST,
)

Discard Tips

await evo.mca.discard_tips()

Aspirate Parameter Reference

The following parameters are accepted by mca.aspirate() as keyword arguments or via MCAAspirateParameterSet:

Parameter	Type	Default	Description
`volume`	Number	auto	Volume in µL aspirated by every mounted channel. Defaults to `min(free tip space, available source volume)`.
`liquid_class`	EvoLiquidClass	auto	Supplies the plunger physics (calibration, per-phase speeds, air gaps). Defaults to an uncalibrated class.
`pipette_mode`	AspiratePipetteMode	SURFACE	Descend relative to the liquid `SURFACE` or the container `BOTTOM`.
`liquid_offset`	Number	auto	Z offset in mm relative to the pipette mode. Defaults to `min(0.5, liquid level)`.
`offset`	Vector	(0,0,0)	XY offset in mm added to the A1 reference well. Use `liquid_offset` for Z.
`follow_liquid`	bool or Number	False	Track the falling liquid level during aspiration. `True` derives the distance from the volume.
`pull_out_distance`	Number	0	Distance in mm to slowly retract the tips out of the liquid afterward, to reduce wetting.
`end_z_offset`	Number	auto	Height in mm above the container the head retracts to afterward. Defaults to the traverse height.
`min_traverse_height`	Number	auto	Z the head raises to before the X/Y move. Defaults to the configured `min_traverse_height`.
`mix_cycles`	int	0	Number of aspirate/dispense cycles to mix the source beforehand. `0` or omitted disables mixing.
`mix_liquid_offset`	Number	auto	Additional Z offset during mixing.
`mix_volume`	Number	auto	Volume aspirated/dispensed per mix cycle. Defaults to as much as tip and well can hold.

Dispense Parameter Reference

The following parameters are accepted by mca.dispense() as keyword arguments or via MCADispenseParameterSet:

Parameter	Type	Default	Description
`volume`	Number	auto	Volume in µL dispensed by every mounted channel. Defaults to `min(tip content, free target volume)`.
`liquid_class`	EvoLiquidClass	auto	Supplies the plunger physics. Defaults to an uncalibrated class.
`pipette_mode`	DispensePipetteMode	SURFACE	Descend relative to `SURFACE` or `BOTTOM`. `JET` is not supported by this head.
`liquid_offset`	Number	auto	Z offset in mm relative to the pipette mode.
`offset`	Vector	(0,0,0)	XY offset in mm added to the A1 reference well.
`follow_liquid`	bool or Number	False	Track the rising liquid level during dispense.
`pull_out_distance`	Number	0	Distance in mm to slowly retract the tips out of the liquid afterward.
`end_z_offset`	Number	auto	Height in mm above the container the head retracts to afterward.
`min_traverse_height`	Number	auto	Z the head raises to before the X/Y move.
`mix_cycles`	int	0	Number of aspirate/dispense cycles to mix the destination afterward.
`mix_liquid_offset`	Number	auto	Additional Z offset during mixing.
`mix_volume`	Number	auto	Volume per mix cycle. Defaults to what the tip and destination hold before the dispense.
`touch_side`	bool or Number	False	`True` derives the wall-touch distance from container geometry after dispensing; a Number sets it directly.
`touch_side_direction`	TouchTipDirection	EAST	Direction to move the tips against the well wall after dispensing.

mca_plunger_steps_per_ul on TecanFreedomEvoConfiguration (default 200) converts µL to plunger steps for the whole head. Only adjust it if every liquid you pipette is off by the same factor or an order of magnitude — for individual-liquid corrections, use a custom liquid class instead (see Liquid Classes).

Tip Handling

Picking up and dropping tips with the Tecan Freedom EVO MCA96 head.

Using the Gripper (RoMa)

Moving labware around the deck with the Tecan Freedom EVO's Robotic Manipulator Arm.