>Date: Thu, 19 Aug 1999 06:14:45 -0400
>From: lpwenk@netquest.com (Wenk, Lee & Peggy)
>Subject: Re: Frozen secioning fat tissue
>To: Alan Bright <Bright@dial.pipex.com>
>Cc: HistoScientific <histosci@shentel.net>, histonet@pathology.swmed.edu
>Mime-Version: 1.0
>
>
>
>Alan Bright wrote:
>>
>> Dear Beth,
>>
>>  . . . To overcome the problem, you will have to spray the specimen, knife &
>> anti-roll plate with a refrigerant spray (Cryospray) to get your fatty
>> sections.
>
>Oh NO!!!! NEVER use a cryogenic spray in a cryostat!!!
>
>The Federal Registry and CAP prohibit this, as it can cause
>droplet, dispersion, etc. of the tissue and air in the cryostat,
>which will then fly out of the cryostat, which you can then breathe.
>Which can then infect you with whatever the patient(s) had in
>the tissue fragments hanging around in your cryostat.
>
>Lower the temperature of the cryostat, or freeze the tissue
>in liquid nitrogen cooled to -50 degrees C (there are machines
>available that do this. We bought ours from Shandon-Lipshaw.)
>But do NOT use the cryogenic spray!
>
>*********************
>
>Peggy A. Wenk, HTL(ASCP)
>William Beaumont Hospital
>Royal Oak, MI 48073
>>

Peggy,
	Perhaps spraying is not such a good idea in this instance with, as
you say, Federal Registry and CAP prohibition. But, can I raise the matter
of cryostats fitted with vacuum debris collector. Although they have
filters do they really, or can they really, filter out prion particles. I
would be a bit more afraid of a constant airflow out the rear of a cryostat
than a quick blast of  coolant. Plus, some models of cryostat have fan
coolers, again giving a gentle breeze of air around the cryostat. Open the
lid and what will you get straight in the face and up the nose.
Ian.


>> Best Regards
>>
>> Alan Bright
>>
>> Bright Instrument Co.Ltd.
>> St Margarets Way
>> Huntingdon
>> PE18 6EB
>> 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: HistoScientific <histosci@shentel.net>
>> To: histonet@pathology.swmed.edu <histonet@pathology.swmed.edu>
>> Date: Tuesday, August 17, 1999 04:18
>> Subject: Frozen secioning fat tissue
>>
>> >Histonetters,
>> >
>> >We just completed a study consisting of mouse fat.  This fat was taken
>> >from around such tissues as the uterus, heart, etc.  We used a cryostat
>> >made by Microm and had it set at everywhere from -18 to -35 degrees.  We
>> >left the tissue in the cryostat overnight and still no luck.  We could
>> >not get a section no matter how thick or thin we tried cutting them.  We
>> >then tried Histofreeze, still no luck.  To make a long story short, we
>> >ended up giving "fat smears".  We have never had problems with our
>> >cryostat and the techs that were working on this project had over a
>> >century of experience with frozens.  Maybe Instrumedics could have come
>> >to the rescue!
>> >
>> >Beth Poole
>> >Histo-Scientific Research Labs.
>> >107 Killmon Road
>> >P.O. Box 30
>> >Basye, VA  22810
>> >(540)856-2222
>> >histosci@shentel.net
>> >
>> >
>

Dr. Ian Montgomery,
West Medical Building,
University of Glasgow,
Glasgow,
G12 8QQ,
Scotland.
Tel: 0141 339 8855 Extn. 6602.
Fax: 0141 330 4100.
e-mail: ian.montgomery@bio.gla.ac.uk