[Histonet] Osmium Tetroxide Protocol

[Connie McManus]

Margaret Horne Wrote:
>>>Double gloving can be uncomfortably tight. 
I found that a nitrile for the inner glove and a latex for the outer 
glove is comfortable for me but it depends on the fit of the gloves 
you use . In a pinch I have used two pair of latex.<<<<

Good idea to 2X the gloves, but has anyone checked to see what TYPE of
glove is best to use with OsO4?  I remember an incident that happened
many years ago about someone who was using a heavy metal compound of
some kind (mercuric, as I recall).  She used latex -- or manybe it was
nitrile --gloves.  The compound went right through the gloves.  It was
extremely toxic and the woman died.  I wish I could remember all the
details of this thing.  It made national news. I always think of this
when protecting myself from toxic chemicals. 

Anyway, check the MSDS on OsO4 to see what kind of gloves are best to
wear.

This also reminds me of the good old days before safety was observed in
the labs.  When I was learning EM, we handled OsO4, Uranyl nitrate, lead
citrate all without gloves.  We tried to be very careful, but I can
remember getting black on my fingernails and on my fingers from the
OsO4.  Who knows what else I contaminated myself with... 

Connie McManus
Utah Veterinary Diagnostics Laboratory
Utah State University
Logan, UT
Phone:  435/797-1891
fax: 435/797-2805


-----Original Message-----
From: histonet-bounces <@t> lists.utsouthwestern.edu
[mailto:histonet-bounces <@t> lists.utsouthwestern.edu] On Behalf Of Margaret
Horne
Sent: Wednesday, May 26, 2004 8:57 AM
To: histonet <@t> lists.utsouthwestern.edu; mprice26 <@t> juno.com
Subject: Re: [Histonet] Osmium Tetroxide Protocol

Hi , when I handle osmium I always :

a) Carry the Osmium to the fume hood in a plastic container . ie. 
the Osmium solution is in a glass jar with a ground glass stopper 
and heavily parafilmed. Also the jar is covered in aluminum foil ( to 
avoid degradation from the light). This jar is Always carried about in 
a plastic container with a lid. Heavy rubbermaid or tupperware is 
good. Note that you will see the plastic container turn black over 
time with the Osmium fumes escaping. We keep it in the " Dirty " 
fridge , not the " Clean" fridge with our antibodies.

b) The plastic container is opened in the fume hood and I wear a  
labcoat and am Doubled Gloved. If the outer glove shows areas of 
black , then the glove integrety has been compromised and I 
replace the outer glove.  Double gloving can be uncomfortably tight. 
I found that a nitrile for the inner glove and a latex for the outer 
glove is comfortable for me but it depends on the fit of the gloves 
you use . In a pinch I have used two pair of latex.

c) Any glasswear that I use , I leave in the fume hood overnight for 
the fumes to evaporate.

d) I keep a container of oil in the fume hood when i am working with 
the osmium so I can pour oil on a spill if necesary or to neutralise 
the osmium if mixed with , say , blood , because it binds to lipids 
preferentially. I have used vegetable oil but it goes rancid over time. 
Mineral oil is fine.
     
      
        Remember that osmium fumes alone are sometimes used to 
fix tissue.  So working without proper ventilation means your 
eyeballs are going to become fixed.  Insist on a proper fume hood.


                       Other than that , it is not bad stuff to work
with :-)

                                                    Margaret

ps. remember that osmium penetrates only 1 mm in depth so your 
tissue has  to be diced small.


Margaret Horne ,
Histology Teaching Assistant,
Dept. of B.SC.,
Atlantic Veterinary College, U.P.E.I.,
550 University Ave., Charlottetown,
P.E.I.,  C1A 4P3 
Canada


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