tissue shrinkage

[PC 1340]

Hello everyone!

I am currently performing whole mount in situ hybridization on 18 
somite and 24 hour zebrafish embryos. I am using anti-DIG 
conjugated to Alkaline Phosphatase as the secondary antibody 
and BCIP/NBT as the substrate for the color reaction. When the 
color reaction is stopped and I look at the embryos to analyze 
them, I notice that the embryos have shrunk, or are dehydrated. Is 
it possible that the type of label I am using is causing this? What 
else could it be? What can I do to prevent it, if anything, and is 
there any way to reverse the "shrinkage"? If there is anyone that 
has any hints or advice for me, I would greatly appreciate it!!! I have 
been searching for answers and haven't been able to find any help 
yet. Thank you!