I am having some troubles stamping BSA onto Stunner/Lunatic Plates from Unchained Labs. I have tried using the liquid classes/liquid correction curve provided by this automation forum but I am not getting too much luck filling the full plate. I am serially diluting BSA from 300 mg/mL row by row on a 96 well plate and have Hamilton STAR stamp the solution to the stunner plate. I am dispensing (jet empty tip) very close to the well bottom, but I am getting empty volume on random location. Only about 50 percent of the wells are filled. Any idea on where the problem could be?
It’s been a while since I’ve worked with Stunner plates, but if I remember correctly the sample volume for those plates is 2uL? If that’s the case, I think a jet empty dispense is going to be difficult to make robust. First thing I’d check is that your tips are actually aligned with all 96 microwells and you’re not just dispensing onto the surface of the plate.
If that looks good, you may have better luck using a surface dispense liquid class and reverse pipetting. For example, aspirate 3uL, dispense 2uL, allow a few seconds settling time for the microwells to “pull” the liquid in, then throw away the remaining ~1uL.
Tecan specific advice here, but it probably translates about the same.
Slight volume over-dispense - very slow dispense speed and likely 0 or 1 stop flow rate. Try to create a hanging droplet then slowly lower it down or side-touch to start the capillary action without forcing the liquid thru the chip with the plunger.
Thanks both for your input! It seems like I made quite a bit of progress getting the right volume into the plate, but I am getting this error once in a while. Sometimes it doesn’t appear at all, but sometimes it’s on quite a few wells. I know the volume is delivered from the absorbance spectra but the result say I have a pump error code 1. I am following the part volume surface dispense mode and touching off as the second dispense.
