Artifact: poor fixation or inadequate slide drying

<< Previous Message | Next Message >>
From:Adrienne Vair <>
Content-Type:text/plain; format=flowed

Our pathologist's are concerned with the poor nuclear morphology they have 
been routinely seeing for many years; foamy appearance, muddy nuclear 
staining (H&E).  I suggested that we look at extending the time in 10% 
formalin as up until then, surgical specimens were received throughout the 
day from the O.R. in 10% Neutral Buffered Formalin (NBF) and most were being 
processed the same day with the exception of bowel, uterus, and breast 
tissue which were being opened and fixed 24 hours. We extented the fixation 
time to a minimum of 24 hours for all surgical specimens including 
colposcopy, endoscopy and fine needle biopsies but to no avail (and the 
increase in turn around time concerned the physicians). The morphology 
remained poor. I looked at temperatures of all reagents during processing 
and embedding, and checked the pH of the 10% formalin being made up and used 
routinely. I stopped using the microwave oven to dry slides as I could not 
find any literature to confirm that microwaving a rack of 20 slides for 7 
minutes at full power (with small containers of water in the oven chamber) 
did not affect the tertiary structure of the proteins in the tissues. Nor 
could I find a procedure in the lab or references as to where the idea 
originated.  They are now being dried at 60 degrees celcius for one hour in 
an oven prior to staining.  The pathologist's insisted that the problem was 
not with fixation but with staining, I made improvements there but as I've 
stated before I could not improve on the nuclear morphology. My question is, 
is this a fixation problem? Is this a slide drying problem as I have 
recently read on this site?  I have read the article on alcohol/xylene 
tissue processing (Journal of Histotechnology March 2000 issue page 45, and 
the ideas seemed feasible but because it is unconventional, I would 
appreciate some other ideas and comments.

Thanks for the input.

Adrienne Vair MLT BMLSc
Histology Supervisor
Medicine Hat Regional Hospital
Get Your Private, Free E-mail from MSN Hotmail at

<< Previous Message | Next Message >>