Getting plates to sit correctly after iSwap movement

Hamilton (Venus) Venus Questions
1

Hi All,

Hopefully this has an easy answer. Every time I move PCR plates from the magnetic block to the plate carrier, one of the corners on the PCR plate isn’t sitting fully on the carrier. I know the slide guides are a little stiff, but I wasn’t sure if there was something I could do to get the plates to lay flush on the carrier.

Thanks!
Kaitlyn

1000010052
10000100521920×1440 105 KB

2

Hello,

Is this happening on one position or anytime you are transporting a PCR plate with the iSWAP? If the former, please see suggestions below. If the latter, confirm that your iSWAP is level and calibrated within spec.

There are a number of ways to get this right:

  1. Ensure proper teaching (X,Y,Z coordinates) of your plate pickup and destination position. Your Z might be a tad too high so when the iSWAP reaches that position, it is not fully seeded in the carrier
  2. Adjust the iSWAP grip height. Decreasing the grip height (distance from top of labware to where you want to grip labware) will raise where the labware is gripped. I have found that gripping a PCR plate a bit higher will help push it into the plate carrier better when being placed
  3. If you are confident in your teaching from option 1 and the pipetting is performing well with those coordinates, you can create a second sequence with your PCR plate labware of which the Z height is a bit lower than the sequence you perform pipetting on. Name the sequences accordingly so you don’t get them mixed up when trying to transport labware vs. pipetting.
  4. Upgrade your carrier to the newer MTAB PCR plate positions. The plastic corner tabs are much more consistent than the older copper tabs :slight_smile:
1 Like
3

Those tabs can be bent in or out to allow for a bit more play in the placement of the plate. It’s a bit of a balancing act with these carriers as they are not intended to be very high precision.

1 Like
4

We had this issue and in the end switched these positions for High Precision ones. Worked better for our process.

These tabbed ones are perfect allrounders, but sometimes you need to give in and get better carriers.

1 Like
5

I know you are using the iswap to place, but if the above suggestions dont work, a hack i have used the paddles to push the plate down - we needed this for one particular position where sometimes the plate didn’t always place flat, and it worked.

2 Likes
6

out of interest - what labware do you mean by high precision ones?

7

out of interest - what do you mean by high position ones? do you have a picture

8

@cdm referring to these ones here. Those are MFX parts so you can exchange them on any position as long as you have a baseplate and “feet”

image
image493×465 34.3 KB

2 Likes
9

Sorry I was on vacation! Thanks for all the suggestions everyone! I’m going to see if I can get it to work with the carriers we have (we are on a startup budget haha), but if that doesn’t work then we will have to buy new ones. Thanks again!

10

From the image, besides the z adjustment that bp11 mentioned to help press the plate down, it looks like the plate is being placed too far to the left, which may mean that the pickup position for the plate on the magnet is taught too far to the right. Making an adjustment on the pickup may help place the plate more in the center of the carrier site.

3 Likes
11

Sorry I haven’t updated this, we’re in the middle of field season and things are crazy. So it looks like I was using the wrong labware definition for the PCR plate I was using. What I thought was a just a regular Cos PCR plate (but off-brand), which had worked for another protocol I used, in fact ended up being closer to a half-area PCR plate. Once I changed that, the robot fully seated the plate in the carrier. Thanks again to everyone who replied, I really appreciate it!

1 Like