Y25-680 - Automating Buffer Addition to Empty Wells During CP on the Tecan

[Stan1520]

Context
During the Concentration & Purification (CP) step on the Tecan, buffer is only added to wells that have a CP request coming from SequenceScape. However, when a plate is sheared, all 96 wells require 120 µl of buffer, including wells that are empty or not populated via CP. Because the system currently does not fill these empty wells automatically, the laboratory team must manually add buffer to all empty wells.

This is only relevant to cherrypicking and not normalisation.

User story
As a laboratory technician, I want the Tecan to automatically add 120 µl of buffer to all wells that are empty during the CP step, so that I can avoid manual buffer addition, reduce the risk of processing errors, and save time by using automation efficiently.

Who are the primary contacts for this story
Lynda D

Who is the nominated tester for UAT
Lynda D

Acceptance criteria
To be considered successful the solution must allow:

• This functionality only applies when the user ticks a checkbox during the cherrypicking submission process (decided to make this user-specified as were not sure how to distinguish safely between norms and cherrypicks in the system).
• After the cherrypick has been planned, any empty wells on the target plate(s) should have 120 µl of buffer added to them. This should be reflected in the Tecan driver files and any other relevant places (e.g. the worksheet).
• All 96 wells must contain 120 µl of liquid after the automated step when processing sheared plates. [We are not touching wells with samples; we add the specified amount to the empty wells]

Additional context
I hear from the team that Tecan used to fill automatically the plate with buffer when 'empty' from a CP paperwork point of view. See comment #5354 (comment)

A working implementation was done in PR #5553 of the research story #5454 , but it has no tests.

Note: 120 µl is the default value. It can be changed in the Cherrypick volume options.

Note that the TecanV3 driver file generator , which reuses tips, is already in production but database records were not created to enable it.

What is left for this story?

• The PR has no unit tests - the changes in PR works when running in SS locally.
• It is not tested with a non-standard "Plate Template" option and it may not work, but it may be irrelevant for the process.
• Another test for partial destination plates would be useful.
• It is not tested with "Control plate & placement type" option.
• Final confirmation of UI options and processes with users (see email conversations)
• Check if worksheet fits on paper when printed [you might want to chop the floating point digits in cells, e.g., e120.00 -> e120]

Deployment notes

Add any details that should be noted when deploying this feature. For example, is a database migration needed, a specifc rake task or other script that needs to be run, a dependency on another application or service that needs to be released first etc?
These notes are intended to ensure the developers releasing the feature know what needs to be done.

Add any other context or screenshots about the feature request here.

[yoldas]

Notes:
Why filled wells matter?
Shearing: mechanical DNA fragmentation. Energy distribution depends on consistent volume. In shearing, empty wells disrupt vibration pattern and lead to uneven fragmentation, i.e. they affect neighbouring wells. That is why buffer is added to empty wells.

I can't understand this statement:
"I hear from the team that Tecan used to fill automatically the plate with buffer when 'empty' form a CP paperwork point of view."

[SujitDey2022]

ld20@sanger.ac.uk looping you in for the query raised.

[SujitDey2022]

Fyi... @yoldas