[Histonet] burn artifact

[Gayle Callis]

What is meant by heat artifact? Describe what he sees. With chips of
prostate, we used to see burned edges on the tissue chips, some type of
cautery at removal.    

There are other guilty sources of heat to create artifact

Embedding center - cassette holding tray may be cooking processed tissues -
how to test, fill unit with melted paraffin and put a thermometer in the
bottom of tray.  Read out on unit may not coincide with thermometer reading. 
		     hot plate
		     forceps warmer
		     paraffin as it comes out of the dispenser
		     paraffin in storage bath

Do you flatten a section with some type of a hot plate/area.  This usually
shows up as large vacuoles in nuclei.  If so, laying ribbon on correct
temperature waterbath with a little stretching motion is sufficient to
flatten and also use the best disposable microtome blades, avoid flattening
with any hot plate. 

How do you test your paraffin baths?  With an immersion thermometer in each
bath? and NOT at the lighted readout on the processor, same for embedding
center. 

How hot is your drying oven - 60C is normal, some use 56 - 58C.  Forced air
dryers often are very hot, in fact too hot. 

At 03:28 PM 6/16/2004 -0700, you wrote:
>Hi All,
> 
>One of our Pathologists is complaining about a "burn artifact" on his GYN
slides. We lowered the temp of our paraffin baths to 58 degrees in hopes
that they would look better, but he still is seeing this artifact. We
process the tissues for about 5 hours total.  Anyone have any ideas about
what may be causing this? 
> 
>Thanks,
> 
>Michele
>
>
>		
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Gayle Callis
MT,HT,HTL(ASCP)
Research Histopathology Supervisor
Veterinary Molecular Biology 
Montana State University - Bozeman
PO Box 173610
Bozeman MT 59717-3610
406 994-6367 (lab with voice mail)
406 994-4303 (FAX)