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?
>Michael Jarmulowicz
>Consultant Histopathologist, Royal Free Hospital, London. UK

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