Washing cells without disturbing pellet

Hello!
We do a lot of spinning and washing of cells on our Hamilton and I’m trying to figure out the best way to aspirate the supernatant after centrifugation. Ideally I could use liquid following but when I do that, the tip often hits the pellet (there is some variability in the volumes so I am overaspirating to make sure the residual volume is the same in all the wells). My workaround has been to create a plate with dead volume about the size of the cell pellet. This works great and I can do liquid following, but now I want to be able to transfer the cells but I can’t get below the dead volume. Although the dead volume works, I am hoping someone has found a better way… Thanks!

you can create another labware and use the 2nd labware for cell resuspension.

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slow aspiration would help, also use fixed height.

Then move up and to the same again in the same well to remove as much of liquid that might have collected in those 2-3 seconds.

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Thank you for the responses. @Pascal-the slow aspiration makes sense and I will test that.
@chips-a-hoai For the 2nd labware, is it possible to change the labware mid-protocol? If so, can you give me a brief how-to?

You can just add another labware on top of your existing labware on the deck editor. This will create automatically create another sequence which you can then use.

I’d suggest using Virtual Labware Library to adjust the pipetting heights here.
If you know the height which is the max pipette height for your plate not to disturb the pellet, you could virtually ‘move’ the plate by this height before the washing steps (so the tips don’t go to the very bottom). You’d just need to virtually move it back after the pipetting step.

This option does not require changing the labware definition or adding any additional labware to the deck :slight_smile:

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Thank you Chips and Magda! I’ll go ahead and try the adding labware on top first since that will be the easiest. The virtual labware sounds like a good option too if that doesn’t work out!