Hi there!

I'm wondering if anyone out there has ever been successful in osmicating
tissue and then processing through GMA?  If so, would you be willing to
share your procedure?

I'm trying to preserve a neutral lipid in liver, lung and spleen.
Originally, I was infiltrating tissue in increasing concentrations of GMA
monomer to preserve the lipid and avoid processing through to absolute
alcohol.  However,  I recently read in an article by Gerrits and Horobin in
the Dec. 1996 issue of Journal of Histotechnology that says this actually
extracts most all neutral lipids.  In an effort to preserve more lipid, I
took pieces of tissue and cut them into pieces no more than 1.5 mm square in
size.  After NBF fixation, they were rinsed in buffer, osmicated for 1 hr in
1% osmium and rinsed in buffer several times again.  The tissue was then
processed down to absolute alcohol and infiltrated in GMA overnight under
vacuum as per our nomal processing schedule.  When the tissue was cut,
there seemed to be very poor infiltration of the GMA into the tissue, most
likely from the osmium.  I'm wondering if longer infiltration in GMA would
have helped, or does the osmium just not allow the GMA to penetrate?  Before
I spend anymore time on something that may be a futile endeavor, I'm hoping
someone out there has tried this and can share their wisdom.

Any advice in this manner would be greatly appreciated!

Emily Yandl
emily.yandl@genzyme.com