Re: Use of Michel's medium for renal biopsies
Mike, I have been doing IF on renal biopsies for 15 yrs with about 90%
of them coming to me in Michel's. Made my own for about 10. My renal
pathologists would NOT want to make a call of a specific IC disease on
our LM tissue. We use Zamboni's for the LM/EM. It isn't just the
presence of the IC deposits its the pattern/intensity and localization.
That's why we still do IF even though we can do all the same markers by
IHC. Michel's is essentially a close to saturated Ammonium Sulfate
solution so it acts to preserve the IC deposits. It is not a very good
fixitive for morphology but it does "fix" the IC deposits so calling it
a fixative isn't wrong. I still consider it a Transport Media. It is
best at allowing room temp transport of these biopsies to the lab. We
get samples from as far away as New Mexico(FedEx) and all over Central
New York. The extreme max is about 5 days. I prefer 3 or less. I
simply wash the samples (tHIS IS EXTREMELY IMPORTANT) for 3 times in PBS
for 10 minutes each, blot off excess buffer, freeze in OCT section fix
in acetone and stain. I have adapted my Biogenex Optimax to do the
staining. We love it!!! If you use it,(Michels) let the sampling
docs/clinics know to store it and use it at ambient temp. Cold temps Ie
4c will precipitate the salts. This changes the pH and really can make
a difference. I've been there and seen that. The pH is also extremely
critical. We use a commercial RTU version and still pH it weekly as
standard QA. I have done H&E, Congo Red and PAS on these frozen
sections in a pinch (Bad sampling in which my IF piece had the only
gloms) with pretty decent success. They don't look great but they work.
If you wash well before freezing and fix the sections quickly there not
bad. I've also done tons of skins,lungs nerves and they all are OK. I
prefer fresh for nerves though. Lung tissue is probably the least
damaged by the Michels. Probably because it's made to shrink and
expand!!! If you need any more info on procedures or recipes, feel free
to email. Bottom line, No problems using Michels if you follow the rules.
Jarmulowicz, Michael wrote:
>I need to provide a renal biopsy service to a remote site. I am happier
>using immunofluorescence (IF) on fresh frozen tissue rather than
>immunoperoxidase on paraffin processed tissue. Michel's medium appears to
>be used successfully for skin biopsies and IF, although I have no personal
>experience of its use.
>Can it be used equally well for transport of renal biopsies for IF, and has
>anyone experience of it in this field?
>Consultant Histopathologist, Royal Free Hospital, London. UK
<< Previous Message | Next Message >>