I'm not certain that carbon birefringes when viewed
with polarizing lenses. Formalin pigment will, as does silica and asbestos. But
I don't think carbon does.
Carbon will resist "bleaching" with potassium
permanganate and sulfuric acid, while this will bleach out melanin.
2 slides of the patient tissue, on silane or
poly-L-lysine, dried for a couple of hours at 60 degrees C. (This procedure
tends to pull tissue off slides.) And 2 slides of melanin, also on the same type
subbed slides and dried of same. Use another patient's case where there is
carbon in lung tissue, prepare 2 slides of this the same way for your carbon
Deparaffinize all 6 slides to water. Keep 1 pt.
slide and 1 control slide in water.
Place the other 1 pt. tissue and 1 each of the
other controls (carbon lung and melanin) in a solution of 99.7 mL d. water + 0.3
mL sulfuric acid + 0.3 g potassium permanganate for about 1 hour at room
Gently rinse in d. water.
Remove excess brown-colored potassium permanganate
from tissue with 1% oxalic acid for 1-2 minutes.
Gently rinse in d. water.
Combine all 6 slides together. Stain with
The melanin will be gone from the treated melanin
control slides, but will still be there on the untreated control
The carbon control will remain positive in the
treated and untreated.
Then look at the patient's tissue - treated and
That's all I can think of to do at a histology lab
An EM scope with metal analysis would work, as
would micro-incineration analysis. But those involve specialized
Subject: RE: [Histonet] Black pigment on
As our pathologist
was explaining his problem to me while we looked at the slide in particular
under his microscope, he said that Carbon was not the item in question as it
does not become refractile when he polarizes/darkfield his microscope (to be
honest he was whizzing objectives and filters so fast I could barely
follow him!). I know carbon is very common in lung, but to my eye as
well, it is too fine and regular to resemble the stuff I usually
-----Original Message----- From: firstname.lastname@example.org
[mailto:email@example.com] Sent: Wednesday, October 29, 2003 3:31
PM To: Kathy.Johnston@CLS.ab.ca Subject: Re: [Histonet]
Black pigment on Bronch Lavages
dear kathy, how have you ruled out carbon, as this is so common. peter h.
-----Original Message----- From:
Kathy.Johnston@CLS.ab.ca Sent: Oct 29, 2003 1:30 PM To:
firstname.lastname@example.org Subject: [Histonet] Black pigment on Bronch
One of our pathologists and
myself have been trying to identify some black intracellular pigmentation
in a bronch lavage. We have ruled out carbon, and bleaching the section
did not work, therefore is not melanin. It is a very fine dark black
pigment and appears quite uniform in shape and size. Our pathologist is
thinking that it is lead (the patient is a long time professional painter),
but lead stains are negative. My other thought is aluminum deposits but
have not yet stained for this.
I am hoping someone on the
"Net" may have some idea of what this may be, and if there is a method
for demonstrating it.