[Histonet] Hematoxylin streaking

[Bernard Paniccia]

Hello histonet!

Long time, first time.

My lab recently transitioned from hand staining for our routine H+Es to
using the Leica autostainer XL. The machine seems to work fine and the
protocol is nearly identical to our hand staining one. The problem we've
run into is that there is a streak of residual hematoxylin remaining on
each slide. Plus slides are worse than non-plus slides. I've tried it with
Richard-Allen Gill Hematoxylin and Surgipath Selectech Hematoxylin 560 MX
and the streaks are still there.

Note the streaking doesn't occur when I hand rinse the racks directly under
sink water rather than in the wash bins of the autostainer. Also we use a
regressive stain.

Has anyone seen something like this before? Any trouble shooting tips? Is
it possible the water pressure of the in-machine rinse is too low? We want
the slides to come out crisp and clear without the streaking purple halo
down the middle.

Thanks so much!

-Bernard