Re: michele's fixative

From:Gayle Callis <>

The original publication is cited in another publication by Jules Elias, J
of Histotechnology, and Michels (correct spelling) fixative was discussed
at great length and found in Histonet archives, including recipe.   

Briefly, it is not a true fixative as is formalin since immunoglobulins are
precipitated in situ by ammonium sulfate, this precipitation is reversed by
rinsing with Michels buffer (in which ammonium sulfate has been dissolved
for "fixative" portion). When using Michels "fixative", timing is essential
and biopsies (kidney, etc) should be rinsed, then snap frozen for
immunohistochemical (fluorescent technics) with best results in 72 hours.
This was discussed at length by Elias, who tested time of fixation and best

Sorry for repeat of recipe, was done to show buffer vs fixative and what
ppts immunoglobulins.

Michels Buffer
> >1M potassium citrate, pH 7.0            2.5 ml
> >0.1M magnesium sulfate                   5.0 ml
> >0.1M N-ethyl malemide                      5.0 ml
> >d H2O                                                 87.5 ml
> >* Mix well and store at 2-8C.   Exp. 1 year
> >
> >Michel's Fixative
> >Michel's Buffer                                    100ml
> >ammonium sulfate                                55gm
> >Adjust pH to 7.0-7.4 with 1M KOH.  Store at 2-8C.  Exp. 1 year
> >

At 02:23 AM 1/13/01 -0500, you wrote:
>On Fri, 12 Jan 2001 wrote:
>> Michele's fixative can be bulked purchased or even small quantities from 
>> Poly-Scientific, at a good price and has a shelf life of about a year.
>I've missed a lot of HistoNet messages lately, but could someone 
>please give all of us chapter and verse for this Michele's fixative? 
>What's in it, and what's it used for, and where is the published
>evidence for its merits relative to other fixatives?
>Sorry if I'm repeating a well-worn theme. If the answers are
>all in the archives, let me and all others know!  Our universiy's
>computer dept has now repealed its exclusion of and many 
>other university servers that would not (if I understand it rightly) 
>spend about $1500 a year to meet the ORB standards for refusing
>to relay spam. Here we were almost completely free of spam while
>the exclusion was in force. If every server cleaned up its open
>relays and passed the ORB test we would all get better service.
>If you've read this far and forgotten, this message's principal
>purpose is to ask for the recipe for Michelse's fixative, with
>references.  Enough said!
> John A. Kiernan,
> Department of Anatomy & Cell Biology,
> The University of Western Ontario,
> LONDON,  Canada  N6A 5C1
Gayle Callis
Veterinary Molecular Biology
Montana State University
Bozeman MT 59717-3610
406 994-4705
406 994-4303

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