[Histonet] Re: Bird head stored in 70% alcohol and possible decalcification

[Gayle Callis]

You wrote: 

 

I have an adult bird skull that fixed with formalin and then has been stored
in 70% ethanol.  

I have seen the post that the sample stored in 70% ethanol can be walking
back through to series of ethanol to water and can be decalcified if it
needs to be. 

 

I am wondering if anybody has done this and there is any side effects from
decalcification after going through dehydration and rehydration of a sample
compared to a general straight forward protocol from decalcification to
dehydration? 

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I have, in the past, when a weekend arrive, I interrupted acid bone
decalcification by removing it from acid decalcifier, a quick water rinse
and immersed into 70% alcohol before returning bone to fresh acid
decalcifier the next working day. The bones always decalcified without
problems but I am sure the decalcification took longer since partially
decalcified bone had to rehydrate.  I later learned more about dipolar (hope
I said that correctly) alcohol slowing and/or stopping ionization of calcium
and ceased using 70% alcohol to interrupt acid decalcification.   I now use
NBF to interrupt decalcification.  Interestingly, I learned the alcohol
technique from the AFIP bone pathology lab.     

 

Alcohol is put into Perenyi's  nitric acid decalcifying solutions to slow
down or control very rapid nitric acid decalcification.     

 

You did not say how big the bird skull was?   I suggest immersing the skull
back into NBF to let it totally rehydrate for several days (depending on
skull size and if the brain is present).  I suggest changing NBF if you
rehydrate longer than a day.   You don't need to go back through an alcohol
gradient since many processing schedules have tissue samples  going from NBF
directly into 70%.   If you leave residual alcohol in the bones, the acid
decalcification could be slower and hopefully not retarded in any way.


 

It certainly is worth a try.   Good luck.

 

Gayle M. Callis

HTL/HT/MT(ASCP)