osmiumtetroxide enhancement of immunocytochem.

[Andrew Ray]

In article <40vpdo$m22 at agate.berkeley.edu>, <Noone at uclink.berkeley.edu> writes:

>
>>>I have done immuno against parvalbumin in brain tissue and staining is 
present
>>>but weak.  I've read that one can use osmium tetooxide to enhance 
visualisation
>>>of the precipitate from the DAB reaction.  However, I need specific
>>>instructions about how to use the osmium to do this.  If you can help me 
out,
>>>post in the
>>>news group or email me at kopl   that is kopello at eden.rutgers.edu.
>>
>>hi Michael,   I can't provide the method but I thought you could do with
>>some OH & S stuff. Osmium tetroxide is mega- dangerous. It is both a strong
>>poison &  mutagenic.
>
>I don't recommend using Osmium tetroxide to enhance DAB staining, unless you 
want to investigate your tissue under the electron microscope. 

We get excellent results with parvalbumin - fibers, cells, sometimes even 
terminal fields.  We use Ni ammonium sulfate, but don't have to to get good 
staining.  Are you sure you're using a high enough concentration of primary or 
secondary (or tertiary if present) antibody?  The other thing to wonder is if 
you are using a long enough incubation in the DAB (or even in the Ab's).  It 
doesn't take much of a change in concentration or incubation to make a large 
change in your labeling.  Good Luck.

Andrew Ray
Emory University
Dept of Neuroscience
aray at emory.ed