[Histonet] Is specimen too cold for cryosectioning?

[Rene J Buesa]

Putting you thumb over the specimen will slightly increase its temperature but I do not think will improve how it cuts, besides you being exposed to whatever may be in the specimen, that is unfixed.
Too cold specimens will be "tamed" by changing the blade angle and the speed of sectioning.
A small difference of ±2ºC should not have any effect. You have also to remember that friction from sectioning will alter the temperature of the specimen, as well as sectioning with the cryostat door open.
Ability to section is the key.
René J.



________________________________
From: arjun ruhella <ruhella.arjun <@t> gmail.com>
To: histonet <@t> lists.utsouthwestern.edu 
Sent: Thursday, September 20, 2012 2:39 PM
Subject: [Histonet] Is specimen too cold for cryosectioning?

Dear all, 

I have heard a little trick in cryosectioning where, if the specimen is too cold, one put thumb on the specimen and then cut immediately. I have a question related to this. 

Q1 = My cryostat temperature cannot be increased above -20C (a problem needs to be fixed). I usually tend to cut my specimen at ~-18C. As i was bound to cut the specimen at -20C, i was experiencing chattering or splintering in the sections. I though this was because the specimen was very cold. When i rub my thumb on the specimen for a while, i was able to get 2-4 decent sections, but the chattering started again. Is this a CONCRETE evidence that the chattering is due to specimen being cold? 

Q2 = Does sectioning difficulty can happen with as small difference as -2C (-18C vs -20C)? I heard ppl saying that -2C will not make any difference in sectioning. 

Hope to hear from someone soon! 

Sincere thank you! 
AR


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