Protocol Cookbook

384 Plate Well Filling with 8-channel pipette

In the Opentrons API, the clearest way to direct an 8-channel pipette to a location is to use myContainer.rows(row_number), which returns a WellSeries object representing all the wells in a row.

For a 96-well plate, you can simply specify my96Plate.rows(row_number), which will represent all 8 wells in that row.

However, for a 384-well plate, an 8-channel pipette will fit into every other well in a row. The 8-channel can fit into A1 C1 E1 G1 I1 K1 M1 O1 of a 384-well plate, not A1 B1 C1 etc.

my384Plate.rows(row_number) will represent all 16 wells in a row. To get every other well starting from the A column, we can do row.wells('A', length=8, step=2). And to get every other well starting from the B column, do row.wells('B', length=8, step=2).

from opentrons import containers, instruments

plate = containers.load('384-plate', 'B1')
trough = containers.load('trough-12row', 'C1')

tiprack_1 = containers.load('tiprack-200ul', 'A1')
trash = containers.load('trash-box', 'E1')

p200 = instruments.Pipette(
    axis="b",
    max_volume=200,
    tip_racks=[tiprack_1],
    trash_container=trash)

# create a list of alternating wells for each row,
# first starting from A then starting from B:
# [A1-O1, B1-P1, A2-O2, B2-P2, A3-O3, B3-P3, ...]

alternating_wells = []
for row in plate.rows():
    alternating_wells.append(row.wells('A', length=8, step=2))
    alternating_wells.append(row.wells('B', length=8, step=2))

# to transfer from the trough to every well in the 384 plate:
p200.transfer(50, trough.wells('A1'), alternating_wells)

Dispensing at the bottom while filling a 384 plate

To dispense at the bottom of every well in the 384 plate, we can take the first well from each row and use the Well.bottom() method to specify the bottom of the well.

In the Opentrons API, when you give an 8-channel pipette a single well instead of a WellSeries row, the pipette will place its leftmost channel in the well you specify.

For a 384 plate, you should specify all the A and B wells. Since we already have alternating rows, we will take the first well in each row and specify to use that well’s bottom with .bottom():

alternating_well_bottoms = [row[0].bottom() for row in alternating_wells]

p200.transfer(50, trough.wells('A1'), alternating_well_bottoms)