[Histonet] Re: 70% from NBF

[Rittman, Barry R]

We also used chloroform extensively and found that for some tissues it
was greatly superior to xylene.
Some tissue such as bone can be left in chloroform for extended periods
of time without becoming too hard or brittle. We first noticed this when
some rat adrenals were left in chloroform for 2 weeks (in error) and
still cut beautifully.
The problems we observed were toxicity (we were verrrry careful),the
fact that chloroform does not clear and so care must be taken to mix
contents occasionally to ensure mixing, and most of all the expense
compared to other intermediary agents.
Barry

-----Original Message-----
From: histonet-bounces <@t> lists.utsouthwestern.edu
[mailto:histonet-bounces <@t> lists.utsouthwestern.edu] On Behalf Of Bryan
Llewellyn
Sent: Tuesday, November 29, 2005 11:15 AM
To: Histonet
Subject: Re: [Histonet] Re: 70% from NBF

Talking about chloroform use in the past.  I trained as a lab tech in
the 
early 60s, and the hospital where I did histology specialist training in

London used chloroform exclusively.  The pathologist apparently thought
that 
xylene made tissues too brittle.  I have many times dunked my hand in a 
litre container of it to get a block out.  You wouldn't believe how much
it 
stings, apparently by slightly defatting the skin!  I was told this
after I 
had done it a few times, of course.

We not only used chloroform without any safety concerns at all, but we
also 
redistilled it to save money.  We had an upright, water cooled still
with a 
Liebig type condensor.  It was heated with an electrical coil in a sand 
bath, which surrounded a 2 litre round bottom flask.  There was no
automatic 
cut off for the electricity, and we had to keep an eye on it and switch
it 
off when the flask was almost empty.  Of course, being a very attentive 
teenager at the time I missed it more often than not.  This was usually 
announced by a disgusting smell and billows of white smoke.  I was never

sure whether the smoke was burning fat and stuff, or phosgene, which is 
produced from chloroform.  For those not aware, phosgene is one of the
gases 
used during World War II as a nerve gas.

I have often wondered whether I became a histotech because I was born 
strange, or whether I became strange because of the time I spent
training in 
a place like that!

Bryan Llewellyn


----- Original Message ----- 
From: "Gayle Callis" <gcallis <@t> montana.edu>
To: <Histonet <@t> lists.utsouthwestern.edu>
Sent: Tuesday, November 29, 2005 8:23 AM
Subject: [Histonet] Re: 70% from NBF


> Joseph made some excellent points here
>
> Chloroform is an excellent clearing agent (used it back in the 60's in

> open dip and dunk processors - O.K. so I'm old!) but no one warned us 
> about its carcinogenic nature and there were no safety issue
regulations 
> then.  Take his advice! 


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