Sulfonate Alcian Blue (SAB) is not always as specific as you would like.
Also, if you are using the newer alcian blue dye, it seems to have a
different formulation than the old stuff that I have. The new alcian blue
will not dissolve in alcohol, so the newer dye doesn't demonstrate the
amyloid, while my old dye does.
Old deposits of amyloid do not have beta pleats at regular intervals.
Therefore, the Congo red dye (CR) will still bind, but will not line up one
right after the other | | | | |, but will be more random \ _ | /. When
the CR dye are parallel to each other, they will show the apple green
birefringence with the polarizing microscope. When the CR dye is randomly
arranged, there will be no apple green birefringence.
The other time this happens is with very overfixed amyloid, such as months
in NBF. Too many cross-links with NBF, so the CR dye can't bind right, so
they are not in parallel. We also had this happen once when the autopsy
tissues were fixed in B5 (mercury fixative, long time ago). The resident
knew amyloid was an immunological problem, so put through tissue fixed in
B5. Congo red did not birefringe. So we went back to the NBF stock bucket,
submitted new tissue, and they all were wonderfully green birefringent.
The other problem with the SAB is that, if this is old amyloid, and the beta
pleats are messed up, SAB depends somewhat on the beta pleats. Therefore,
the green will be much paler in older amyloid than with newer amyoid. (The
green is due to to the blue of alcian blue staining the amyloid, and the
yellow of picric acid in the van Gieson also staining the amyloid, so blue
and yellow make green.)
We just had a case of non-birefringing green Congo red at our hospital a
couple of months ago, where it definitely looked by amyloid on the H&E, but
there was no birefringence on the patient's CR (control was great - all 3
times that we repeated the procedure). Ot wasn't a fixation problem, or a
staining problem, but probably an "old amyloid" problem. Our resident Dr.
Tom Fennel just gave a talk on it at our state histology's winter seminar
Jan. 31, 2009. Here's what we did (all three):
1. View the Congo Red stained slides with a fluorescence microscope, such as
in microbiology auramine-rhodamine stain for AFB. When hit with green light,
the CR stained amyloid will fluoresce orange.
2. Use Crystal Violet or Methyl violet staining for amyloid. These depend
upon the carboxyl ions of the amyloid for binding, not the beta pleats. The
amyloid should be violet, with the background blue/purple. However, it
doesn't always demonstrate AA amyloid (some are low in surface carboxyl
ions). So not always as sensitive as CR.
3. Use Thioflavin T or Thioflavin S for amyloid. Staining is (maybe) with
the P component of amyloid, not the beta pleats. Use a fluorescence
microsope, using blue light (FITC filters), and the amyloid will fluoresce
yellow. However, other things also fluoresce yellow, such as fibrinoid
material, JG granules, sometimes elastin, etc. So not as specific as CR.
By knowing your histology and knowing where in the tissue you are thinking
that there are amyloid deposits, the above three alternatives are a nice
addition, for when Congo red is not demonstrating the apple green
birefringence.
Since in our recent case, 3 out of 4 stains demonstrated amyloid (CR
fluorescent, Crystal violet and TFT were all positive, while CR
birefringence was negative), it was diagnosed as amyloid, with, I think, a
note that older deposits of amyloid sometimes demonstrate no birefringence
with CR.
If this person needs help with find staining procedures for CV/MV or
TFT/TFS, could someone email them? I'm on vacation, and don't have access to
my home or work computer.
Peggy A. Wenk, HTL(ASCP)SLS
Beaumont Hospital
Royal Oak, MI 48073
----- Original Message -----
From: "Nathanial nauss" <nsna...@bellsouth.net>
To: <histonet@lists.utsouthwestern.edu>
Sent: Friday, February 27, 2009 10:42 AM
Subject: [Histonet] Sulfated Alcian Blue
I need some help, has any one used the sulfated alcian blue to stain for
amyloid. We have a case that looks like it should be positive but it is not
staining with the Congo Red. Any help would be great.
Nathaniel
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