RE: coverslipping with gloves

From:"Monson, Frederick C."

Coverslipping at the beginning was agony, because one never quite got the
correct amount on the prep, or the stuff was too dilute, or something.
Then, after about 5 years, I was helping a friend to fabricate glass
needles, and we ended up with all of these failures lying on the lab bench -
for days, because neither one of us felt obligated to do so.  Sometime
later, I was at the same bench coverslipping, and I dropped the little glass
rod on the table.  Sticky mess.  I picked up one of the 'failures' and began
to learn a great lesson.

I always used about the same viscosity of mountant (Gum Damar/Xylene) and
with this small wand I began to recover from the mess of coverslipping.
With the tapered glass rod, I quickly learned how deep, or how many times to
dip, the thing to field the correct amount (number of drops) of mountant for
22x22, 24x50, etc.  Then, of course, I learned to wipe the slide and pick up
the coverslip, and I was in heaven.  When I had to train students after
humanity discovered hazardous chemicals, I trained them to do what I did, in
a fume hood.

Gloves?  Never, even when I made up my own Dam(m)ar from the crystals and
had to wait while it 'evaporated' down.  In the old days, there used to be
double funnels through which one could send steam to heat the mix while it
filtered.  I had to over dilute.  I still have about a Liter left, and I
prepared it 8 years ago.  As I grow older, I wonder what will become of that
which remains, and I pine, because it will be treated as "hazardous waste".

The moral is, of course, work out a method that is neat, thus, safer.  


Fred Monson

Frederick C. Monson, PhD
Center for Advanced Scientific Imaging
Mail Drop:  Geology
West Chester University
West Chester, PA, 19383
Phone/FAX:  610-738-0437 

-----Original Message-----
From: J. A. Kiernan []
Sent: Wednesday, April 16, 2003 2:12 AM
Cc: HistoNet Server
Subject: Re: coverslipping with gloves

> Just one quick question.. Do any of you use gloves to cover slip by hand?

I've seen graduate students doing this, and have also
seen the messy results. If there's something as close
fitting as a surgical rubber glove that resists xylene
it might be possible. Some of our grad students and
technicians do their coverslipping in a fume hood, bent
down with their noses almost in the xylene to avoid
banging their heads on the sliding door, and with no
room to move their arms. This also causes bad coverslipping,
and the floor of the fume cupboard is an uneven layer of
dried mounting medium. 

Great numbers of bad slides are produced from valuable 
research materials. Thoughtless following of "safety
precautions" is only one of the causes, but unexplained
regulations result in a lot of wasted time and money. 

A bigger factor is ignorance on the part of principal
investigators and their trainees. The artifacts that 
I see most frequently are due to carelessness that 
surely would never be tolerated in aNY clinical or 
commercial lab. 

About 3 years ago, in the lab next to mine, the 
technician (who had an MSC in biochemistry) was 
dehydrating and clearing mounted sections, washing 
them in water, going to xylene again and coverslipping 
with Permount. Thousands of slides were produced in 
this way, stained (not very well) and then rendered 
unusable. Their crazy procedure was due to a word 
processing error, probably made by a graduate student
who didn't know that water and xylene don't mix.
The chemically literate technician told me that she
knew this but followed the protocol anyway because
it was on the printed sheet.

John A. Kiernan
Department of Anatomy and Cell Biology
The University of Western Ontario
London,   Canada   N6A 5C1

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