Inaccurate MPH Aspiration

Hamilton (Venus)
1

Hi All,

I recently noticed that our MPH is having a hard time aspirating evenly, but only on one labware position. This labware is located at the back of the instrument and the volume is low (2uL). In the past I had no problem with this labware, but after a recent PM the aspiration is spotty and tends to over aspirate. The confusing thing is that this issue does not appear when aspirating other labware positions, only this one.

I parked the MPH over the labware to look at the aspiration height, and noticed that tips located towards the back of the instrument appear to be at a slightly higher Z than tips at the front. However, there have been no issues with tip pickup and the instrument passed FVK2 recently.

I am somewhat flummoxed by the results, as I replaced both the carrier and labware to no improvement and volumes continue to be spotty.

Has anyone else encountered a similar issue with the MPH?

2

Could it be that the labware itself is at the wrong height/ on a tilted surface?

3

Do you observe the same issue on the other tracks: “tips located towards the back of the instrument appear to be at a slightly higher Z than tips at the front”?

Have you tried adjusting the taught position of that problematic labware position, specifically the Z-position?