fixatives

[rjpalmer]

Would anyone care to comment on fixatives that do not contain
formaldehyde or alcohol? A commercial product of this type is known
as Histochoice MB.  Pros/cons?  We are interested in non-dehydrating
fixation/embedding, i.e., aqueous resins.
--
Robert J. Palmer Jr., Ph.D.
Natl Inst Dental Craniofacial Res - Natl Insts Health
Oral Infection and Immunity Branch
Bldg 30, Room 310
30 Convent Drive
Bethesda MD 20892
ph 301-594-0025
fax [phone]

[Tamara Howard]

Take a look at the MSDS - there is ethanol in Histochoice
MB, but no way to tell how much. I've never tried it for
EM.

http://www.nbsbio.co.uk/downloads/MSDS%20HistoChoice%20MB.pdf

Tamara

On Thu, 12 Mar 2009 16:02:37 -0400
  "Robert J. Palmer Jr." <[hidden email]>
wrote:

> Would anyone care to comment on fixatives that do not
>contain formaldehyde or alcohol? A commercial product of
>this type is known as Histochoice MB.  Pros/cons?  We are
>interested in non-dehydrating fixation/embedding, i.e.,
>aqueous resins.
> --
> Robert J. Palmer Jr., Ph.D.
> Natl Inst Dental Craniofacial Res - Natl Insts Health
> Oral Infection and Immunity Branch
> Bldg 30, Room 310
> 30 Convent Drive
> Bethesda MD 20892
> ph 301-594-0025
> fax [phone]

***************************
Tamara Howard
Cell Biology & Physiology
UNM-HSC
Albuquerque, NM
***************************

[Mario-2]

Robert,

I can't help you much with this but I have used a membrane permeable
homobifunctional succinimidyl ester as a "gentle" fixative at 37 deg.
C prior to harsher fixatives for microtubules. It might provide a
useful amount crosslinking by itself but I haven't tried it alone.

Mario

>Take a look at the MSDS - there is ethanol in Histochoice MB, but no
>way to tell how much. I've never tried it for EM.
>
>http://www.nbsbio.co.uk/downloads/MSDS%20HistoChoice%20MB.pdf
>
>Tamara
>
>On Thu, 12 Mar 2009 16:02:37 -0400
>  "Robert J. Palmer Jr." <[hidden email]> wrote:
>>Would anyone care to comment on fixatives that do not contain
>>formaldehyde or alcohol? A commercial product of this type is known
>>as Histochoice MB.  Pros/cons?  We are interested in
>>non-dehydrating fixation/embedding, i.e., aqueous resins.
>>--
>>Robert J. Palmer Jr., Ph.D.
>>Natl Inst Dental Craniofacial Res - Natl Insts Health
>>Oral Infection and Immunity Branch
>>Bldg 30, Room 310
>>30 Convent Drive
>>Bethesda MD 20892
>>ph 301-594-0025
>>fax [phone]
>
>***************************
>Tamara Howard
>Cell Biology & Physiology
>UNM-HSC
>Albuquerque, NM
>***************************

--
________________________________________________________________________________
Mario M. Moronne, Ph.D.

[hidden email]
[hidden email]

[Pertti Panula]

Hi,

We use bifunctional fixatives, which are excellent in selected cases and
far superior to both aldyhydes and alcohol for many immunocytochemical
procedures. For example, EDAC makes a peptide bond  and allows detection
of histamine, GABA, octopamine, and many peptides using ihc. It can be
combined with aldehydes to allow detection of antigens that may require
them.

At best, EDAC will allow dilution of antisera up to 1:1 000 000 without
additional enhancement. This will give excellent signal/noise ratio
(again in a few best cases). Additional advantages include significant
savings in antibody costs. Cons include higher cost of fixative, and
consistency of the tissue (not as hard as aldehyde-fixed). Requirements
for e.g. pH are also different from aldehydes.

There are many descriptions of these. We got started with the fact that
our antisera were made against conjugates prepared with EDAC, and the
classic texts of AGE Pearse provided initial evidence that these agents
work well.

I would never use a commercial agents with unknown contents. I do not
know the product you mention. Fixation is, after all, largely chemistry.

Best regards

Pertti Panula







Robert J. Palmer Jr. wrote:
> Would anyone care to comment on fixatives that do not contain
> formaldehyde or alcohol? A commercial product of this type is known as
> Histochoice MB.  Pros/cons?  We are interested in non-dehydrating
> fixation/embedding, i.e., aqueous resins.


--
Pertti Panula
Professor, Research Director
Neuroscience Center
Institute of Biomedicine/Anatomy
POB 63
00014 University of Helsinki
Finland
Phone: [phone]
Fax: [phone]
Mobile: [phone]
[hidden email]
http://www.helsinki.fi/neurosci/panula.htm