Hello there,
During development of a maintenance method for our STARs I have come across an issue.
A bit of background:
In the past I have been using Agilent Bravo’s quite extensively and to ensure it pipettes correctly it was necessary to do regular check of pipetting barrels. In the company we have developed very robust workflow to facilitate this. It consists of 2 tests and basically covers all demanding scenarios.
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You aspirate eg 50 ul and let the head sit in the reservoir for 5 mins in a way that tips are submerged. Then 45 ul is dispensed and you go up. In the air you dispense 3 ul which should form a hanging droplet. By inspecting droplets, you know whether there is a faulty O ring or some sort of leakage (droplet is not present in that case).
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Aspirate of 5 ul, mix 50 ul for 40 cycles. Go up in the air and dispense again 3 ul and watch for missing or smaller droplets.
This routine has been proved to be very effective and also fast to do. Droplets are easy to observe even on 384 head.
So, I wanted to create something similar for our STAR. The problem is that I do not know how to force the head to stay in the liquid after aspiration besides the settle time parameter of liquid class. After many weird errors I have learned that there is some hidden range of values that is permitted to use.
Therefore, I am asking experts here - is anywhere some documentation of LC parameters allowed ranges? Or is there other way how to force the head to not move out of the well after aspiration?
Thanks a lot for any input!
