Reload a carrier

Hamilton (Venus) Venus Questions
1

Hi all! I’m trying to find the best way to reload a carrier part way through my method. I assume there is a way to do this, but I’m still learning so I could use some help. I was hoping the robot would know that it needed to have the carrier reloaded, but that was definitely wishful thinking on my part haha. I have 8 PCR plates that are going to be used in my method, but I only have 4 positions in my carrier available. I want to have the first 4 plates loaded, and then when they are done being used, I want the robot to pause so I can swap out the current plates for the next set and have it continue where it left off. In my deck layout I have all 8 plates loaded on the one carrier (so 1 & 5 in one spot, 2 & 6 in the next spot, and so on) but I only load plates 1-4 on my initial Load command. Is there a simple way to do this that I’m missing, or is it going to take a bit more work on my end? Thanks!

2

The easiest (ad most dirtiest way) is to create a sequence of your plates to process and follow that sequence.

In the loop, place a GetCurrentPosition step and when the current position hits 384, execute a reload.

3

Hi @InnerKK,

You only need 4 plates on your deck layout for this (unless they are actually different labware types) so no plates superimposed over top of each other.

When a carrier is unloaded, any labware currently on it during the run is effectively removed from the sample tracking database. So if at the start of the run you scan a carrier and barcodes are assigned to the plates on that carrier, then you call an unload command on that carrier, querying those barcodes will return errors. This is because they were effectively removed from the deck layout with the unload step.

So if you’d like to process 8 or more plates and you only have 4 positions, you would basically do the following:

  1. load the carrier at the start of the run
  2. process with liquid handling up to 4 plates that were loaded
  3. do any file handling that needs to be done for those plates
  4. unload the carrier
  5. custom dialog to pause the method and ask for a reload
  6. load the carrier and scan new plates
  7. go to step 2 and repeat for however many plates you need

I hope this helps!

Matt

4

Thank you, this is really helpful!

5

Yeah that is what I was going to do originally, but I wasn’t sure if there was a better, cleaner way

6

Hi Matt, just a follow up question. Would I need to have 2 separate mapping files, one for plates 1-4 and one for plates 5-8?

Also, for tips, does the robot automatically pause if you need to reload the tip carriers or would I need to do the same thing for that?

7

Hi @InnerKK,

It sounds like you would definitely need multiple mapping report steps in your method at the least. But how many depends on how your sequences are managed as well as the naming convention of your mapping report files. If you are processing 8 plates then perhaps you would write your method to have 8 mapping reports generated and the naming convention would utilize the unique barcode of the plate. Or perhaps it’s just one mapping report and you keep appending to it with the next plate’s data. Regardless, what if your method has an unfortunate abort halfway through and you have already processed some plates but you didn’t make any mapping reports yet? In this case, having a generate mapping report command immediately upon completion of each plate might be a good idea. And like I previously said unloading a carrier with labware currently on it removes those labware from the sample tracking database - if you pipette to a plate, unload that plate/carrier, reload that plate/carrier so it is effectively the same sequence and labware ID (but physically is a new plate you swapped out), a mapping report that is then generated for that sequence will not have the previous pipetting data.

Now tips are a different situation altogether. If your tip sequence goes unchecked and you keep using tips you eventually just get a “no more sequence positions available” error. Tip sequences must be checked and custom reloads prompted to the user prior to tip pickups - if enough tips are available then do the tip pickup, if they aren’t then prompt a reload and show a tip edit dialog. Hamilton has created many helpful libraries that take care of common things in methods like this. I’d suggest downloading and taking a look at the STAR Tools demos from the library downloads section of this forum to see how this is done.

Matt

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