Hi,
    This is a notorious staining problem. I thought it might be fixation
related so I ran two slides from the same block in different parts of the
stainer (DAKO = LabVision right?) one slide had uneven staining the other
didn't. The sections were treated identically. Next I thought the instrument
was not level so I checked that. First the instrument was not level, so I fixed
it, then I noticed that depending on where on the machine you are checking it
was never level. The racks were warped, DAKO was fantastic about replacing
them. So, finally the instrument was level and the racks were even. The uneven
staining still OCCASIONALLY reared its ugly head. So we tried changing the
slides (perhaps there was an uneven coating on the slides) Even with uncoated
slides it still occurred.
    The situation is not always there. Often there is no problem at all. I call
this a ghost problem. I really think the solution is occasionally not getting
dispersed properly on the slide. (Yes there is Tween in the buffer) I would
like to hear from people to see how common this situation is. Does anyone using
a Biogenex Optimax see this problem? I'm sure NexEs users dont (the solutions
are basically stirred).
baffled.
Amos Brooks

Jakrobsmith@aol.com wrote:

> Many thanks for all the replies regarding processing machines and the
> autostainer. It seems that everyone loves the VIP. We do not use coated
> slides on our staining machine for our H&Es but you may have solved another
> problem for us. We are also experiencing patchy staining on our Labvision
> immunostainer which could be down to the coated slides.
> Many many thanks to all of you.
> Jackie (Frustrated Histologist) England.