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.
1 Like
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.
1 Like
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 
3 Likes
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!
I used to use this library but don’t have it on my current machines - can you advise where one can find and download this?
@EricSindelar_Hamilton has all libraries shared for LabAutomation, you need to download VirtualLabware_V2 to make this possible.
1 Like
Yes, this virtual labware library has been posted to the Hamilton Libraries shared folder.
You can also set a parameter in the container definition that would prevent the system from ever going past a specified height.
For VENUS five and prior, it’s referred to as Maximum pipetting height:
For VENUS six and above, it has been renamed to Dead volume height:
See below for more details on this parameter:
3 Likes