We are using clone Vim 3B4 to check for prior 'mistreatment' of the tissue -
and we use an enzymatic (trypsin) pretreatment for Vim 3B4, not HIER. This
staining will identify most blocks that have not been properly fixed. Many
of them will still stain with clone V9 (after HIER; e.g. the large melanoma
that is Vim 3B4 negative in the center of the block will be +++ with V9),
thus we do not consider V9 an appropriate clone to check for 'fixation
sins'. In our lab Vim 3B4 is not run on every diagnostic block (as - with
experience - you will also recognize blocks that are a problem based on
their staining pattern with MIB-1, CD4, CD10, to name but a few - and you
can still run a Vim 3B4 afterwards). However, we always run Vim 3B4 on all
blocks that are used in retrospective studies, as we can not be sure how the
fixation procedure was for material that has been ollected 5 or 10 years
ago. Blocks that are negative for Vim 3B4 are usually excluded from
evaluation, although many other antibodies may still work on them.

Andi Kappeler
Institute of Pathology, University of Bern, Switzerland
http://www.pathology.unibe.ch


> >>> "Hagerty, Marjorie A." <mhagerty@emc.org> 7/March/2001 12:19pm
> >>>
> When you run a vimentin on your patient slide to check fixation, do you
> need
> a specific clone? I heard quite awhile ago that it was a specific clone.
> Those of you using vimentin as a test for immunoreactivity, what clone
> do
> you use? I assume (?) that you treat this slide identically to the other
> slides on the case as far as antigen retrieval.
>
> Thanks in advance,
> Marg
>
>
>