Hi Mark, and welcome to the forum!
While there may be a couple options that can help here, Iād like to preface the post by stating that it sounds like your observed CO-RE grip āGet Plateā and āPlace Plateā step performance is less robust than typical, and could be subject to some optimization in order to prevent transport issues entirely. Dropped plates should be extremely atypical.
For starters, Iād double check that your labware definitions are accurate and true to the plate, and also ensure that the taught deck coordinates for your plate positions are representative. Youāll also want to ensure that your grip parameters are optimal. I typically recommend using as accurate a grip width as possible relative to the grip height used, and apply 50% force. For typical MTP style plates, 3mm grip height is good and what I almost always use. Additionally, I like to slow down the Z speed during placement just a bit (relative to default 128.7mms) to around 80mm/s, and use a 1mm press down distance, which provides an additional downwards āshove-likeā movement at the end of placement into the locator.
tabbed carriers were gripping the MTP with enough force where the CO-RE paddles couldnāt pick it up
This also strikes me as abnormal. Would you mind providing a bit more detail here regarding the style of carriers? This should not be an issue under normal circumstances.
While the āCheck if plate existsā feature is certainly useful, I would not qualify it as a requirement for robust CO-RE grip steps
That all said, there are other options to get the channels to interact with a plate after placement has occurred. Youāll see numerous mentions of the STAR Tools suite all over the VENUS section of the forum, which includes a Channel Tools library that features numerous useful custom channel functionality. In your case, there are two functions that may be of interest to you:
Note that neither of these will be particularly helpful if there isnāt a region of the plate that doesnāt have significant adhesive on it.
STAR Channel Tools::MOVE_CheckPlateWithTwoChannels
This is the most similar to the 'Check if plate exists, but allows for some customization. If there are regions of the plate less prone to adhesive residue after peeling, then you can customize the ātap widthā to whatever you want (relative to plate center). Additionally, you have the option to have the two channels that will perform the tap to pick up tips prior to the function. This will significantly decrease contact area relative to two CO-RE paddles.
STAR Channel Tools::PLATE_STACK_CountPlateStacks
This function will use a channel (no tip or CO-RE tool required to be loaded) to āprobeā a stack of labware and return a count of stacked labware present at the site(s). This works by sending a channel down gently in Z until it makes contact with labware dead-center. While this was intended primarily to confirm labware counts loaded in stacks, it also works with āstacks of oneā with unstacked labware. If no labware is present at the sequence site, then the function will yield a count of 0.
Hope this helps!
-Nick
