Dear Stephanie,

Your "Venetian Blind" Artefact should be eliminated if you set your chamber
temperature to -20C or -25C and the object temperature to -8C to -12C.
Please let me know how this works out.


Best Regards

Alan Bright

Bright Instrument Co.Ltd.
St Margaret's Way
Huntingdon
Cambridgeshire
PE29 6EU
England

Tel No:+44 (0)1480 454528
Fax No:+44 (0)1480 456031
Email: AlanBright@brightinstruments.com
Web Site: www.brightinstruments.com


-----Original Message-----
From: Stephanie Moore [mailto:smoore@brandeis.edu]
Sent: 12 January 2001 15:23
To: HistoNet Server
Subject: "Venetian Blind" Artefact


I have recently experienced what I believe to be this artefact while slicing
sections of squirrel brain.  I know that this was not properly sunk and also
that
it was likely in too little volume of paraformaldehyde (4%) fixative.  The
person
who gave me the specimen is not very experienced, but wanted to slice it
anyway.
My question is, does insufficient cryoprotection from sucrose cause
ventetian
blinds?  I use a cryostat set at -20C chamber temperature and -18C object
temperature, and Tussue Tek OCT medium for embedding the specimen.