[Histonet] RE: need help about frozen bladder sections

[C.M. van der Loos]

Dear Izzet Oguz,
A storage temperature of -20C is not cold enought for proper 
preservation of the tissue morphology and structure. That might be 
perhaps the reason why your tissue became so fragile. At snap freezing 
of your tissues the water content will be frozen as amorphous cristals. 
However, between -1 and -40 water cristals will reshape from amorphous 
to needles. It is obvious that the needle structures will damage your 
tissue morphology very badly. At a temperature below -70 this needle 
forming process cannot take place anymore. 
Chris van der Loos
Dept. of Cardiovascular Pathology
Academical Medical Center
Amsterdam - The Netherlands


----- Original Message ----- 
>From  "izzet oguz" <docmichel <@t> netbulmail.com> 
Date  Thu, 2 Oct 2003 09:28:51 +0300 (EEST) 
To  <histonet <@t> lists.utsouthwestern.edu> 
Subject  [Histonet] need help about frozen bladder sections 

we took  bladder sections from rats about four months ago..first we 
froze the tissue in liquid nitrogen. Then left them at -20 C deep 
freeze for 4 months..after that we could not cut the tissues because 
they became so fragile..Any suggestions about this problem will be 
greatly appreciated..Thanks..
?zzet