[Histonet] Re: Liquid nitrogen, mouse spleen - Freezing tissues

[Andrea Hooper]

I second Gayle's technique described below. It is wonderful. After 
spending so many years fixated on isopentane in liquid nitrogen and 
getting cracked blocks in order to adhere with what was 
histologically correct, I have finally moved onto the floating boat 
technique and my frozens look nearly as good as paraffin sections. 
The only difference is that I use metal floating boats (read: 
sterilization trays) instead of plastic petri dishes. This way the 
blocks cool even quicker - better for the tissue and morphology - 
though they still don't shatter.  I finally feel liberated :)



At 9:27 AM -0700 1/4/07, Gayle Callis wrote:
>Yes, your very last suggestion will work perfectly.  We place a 
>plastic petri dish IN the liquid nitrogen, then you can set the OCT 
>embedded spleen in the petri dish.  We have shattered spleen and if 
>we do isopentane cooled by liquid nitrogen, or direct immersion into 
>liquid nitrogen.  Just make sure the petri dish is supported so it 
>does not tip over in the Liq N2, and do not allow Liq N2 into the 
>dish.  You need to replenish the liq nitrogen as it is important to 
>maintain the dish directly in the N2.  In other words, the dish goes 
>canoeing in the Liq N2.
>
>Good luck
>


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