[Histonet] IHC control debate

[Lynette Pavelich]

Hello,
I need help from all of our IHC expert guru's!  We have a debate going
on about the known positive control blocks.  All are FFPE with 8-48 hrs
in formalin.  All have been tested and have been approved for use as
positive controls.  We currently cut the positive control from the block
as needed.
I have learned that some controls do start to deteriorate over time,
tonsils for example.  But, is there a list, an article, SOMETHING that
can guide me so that we can cut some of these controls ahead of time? 
This would not only save tech time, but would further the use of our
controls.  In cutting the block, some of the good control is wasted and
some positives are hard to find.
My argument is that the purchased controls work wonderfully, even after
a very long time and our improved detection kits have improved so much
over the years, it makes this possible.

If there is no published article out there, I implore you experts to
please help us in this area.  Would also like to hear from the technical
experts from our suppliers too!  Until then, the debate continues
on!!!!!!!

Thank you!!
Lynette