[Histonet] fixation and decal of cortical bone

[Nicole Hedgecock]

Hi, All
I would like to fix, decalcify, and embed rabbit cortical bone sections in 
order to do TUNEL staining for osteocyte apoptosis, but I've come across 
conflicts between the literature and an actual, working protocol a colleague 
has shared with me.
That being said, can you store the sample in a fixative for long periods of 
time? i thought that if left in formaldehye or formalin for too long then 
there would be too much cross-linking and antibodies (for IHC) could not 
penetrate. Is over-cross-linking not an issue for TUNEL?
Also, don't formalin and paraformaldehyde break down into formic acid after 
a period of time? I read that formic acid is no good for TUNEL, EDTA is the 
decalcifier of choice.
finally, if you can't store your sample in the fixative for extended periods 
of time (weeks to months), then how can I store it until I am ready to 
decalcify them?

Thanks,
Nicky



Nicole Hedgecock
Orthopedic Research Lab
UCD Medical Center
University of California, Davis

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