Wang reported on the contamination of tissue sections with AFB by the use of
fluorescence microscopy, and if I remember correctly, when he tested the water
in water fountains, he found something like 33% contained AFB. Non-pathogenic,
but we can't tell that on our stains. The paper is in Am J Clin Pathol 51:71,
1969. We (Carson, Kingsley, Haberman, and Race) also reported the
contamination in the 1964 issue of the same journal. We stopped using tap
water for our water baths and began using millipore filtered water that had
already been through a deionizing column and charcoal filter. We always cut a
negative control from the same days workload as the patient case - uterus in
our case. You don't need a positive control cut the same day, just a positive
control with only a medium number of organisms. We also did not use any tap
water in the deparaffinization prior to the carbol fuchsin. AFB organisms have
also been reported growing in 40
gal formalin tanks believe it or not and in the old Fisher Paraffin wafers.
We centrifuged tap water in 50-ml tubes, poured off the supernatent, and
refilled and recentrifuged until we could see some sediment in the bottom. We
took that to Microbioloby and had it cultured to definited prove the presence
of AFB in the tap water.
I would recommend this approach to anyone suspecting tissue contamination.
Freida Carson
--- On Thu, 5/28/09, Akemi Allison-Tacha akemiat3...@yahoo.com wrote:
From: Akemi Allison-Tacha akemiat3...@yahoo.com
Subject: Fw: Re: AW: [Histonet] AFB Recycling Formalin for Fresh Tissue
To: Histonet Histonet@lists.utsouthwestern.edu
Date: Thursday, May 28, 2009, 1:21 PM
Hello,
I responded to Gudrun personally, but I thought that the information I am
supplying him below might be a good educational source for other histologists
who are having similar scenario's for AFB contamination.
I would also like to say that I have an extremely eager histology team that
have expressed an interest in learning theory and practice. Most of my team
are OJT. They have had several pathologists approach them with these concerns
regarding AFB, and because of their knowledge, or lack of it, couldn't fix the
problem. We are starting with the basics and I am giving in-services along the
way.
Hi Gudrun,
They are shipping the recycled formalin directly to the outside hospital
surgery to put their fresh tissues into.
As far as the AFB, we have had intermitant (+) AFB on the edges of tissues,
that has been extremely questionable. We currently are not cutting a negative
(-) positive(+) control on the same water bath as the test sample. That will
be remedied beginning Monday. The water here is also in question. I will be
sending it out for microbacteria analysis.
We are going through a thorough housekeeping and in-service process. We are
starting with the tissue processors, which are currently only changed weekly
(not rotated daily), embedding centers, which have to my knowledge, never been
drained, and the hopper cleaned-out. The water baths are not scrubbed out with
soap and HOT water daily and
covered at night to prevent contamination. The water bath is not skimmed of
excess tissue debris, each and every time another specimen is placed on it.
The Carbol Fuchsin is not being filtered prior to use. The working solution is
currently being poured back into the stock bottle. Need I go on
Akemi Allison-Tacha BS, HT (ASCP) HTL
Histology Manager
Associated Pathology Medical Group Laboratories
105A Cooper Ct. Los Gatos, CA 95032
Cell: 425.941.4287
W: E-Mail: aallison-ta...@apmglab.com
P: E-Mail: akemiat3...@yahoo.com
--- On Thu, 5/28/09, Gudrun Lang gu.l...@gmx.at wrote:
From: Gudrun Lang gu.l...@gmx.at
Subject: AW: [Histonet] Recycling Formalin for Fresh Tissue
To: akemiat3...@yahoo.com
Cc:
histonet@lists.utsouthwestern.edu
Date: Thursday, May 28, 2009, 10:34 AM
Just for interest. Your lab takes the recycled formalin to make 4% neutral
buffered formalin (NBF)? Or do they ship the recycled formalin directly in
bottles to the surgery?
AFB = acid fast bacili?
Do you have concerns, that they produce false-positive AFB stains? I cannot
imagine, that a (hopefully) small number of dead bacili on the surface of
tissue will pretend this. An other question: Isn't there a filter in the
recycler to prevent such contamination?
Gudrun
-Ursprüngliche Nachricht-
Von: histonet-boun...@lists.utsouthwestern.edu
[mailto:histonet-boun...@lists.utsouthwestern.edu] Im Auftrag von
akemiat3...@yahoo.com
Gesendet: Donnerstag, 28. Mai 2009 18:14
An: Histonet
Betreff: [Histonet] Recycling Formalin for Fresh Tissue
Good Morning Histo Land,
I am asking all you out there to give me your input on recycIing formalin.
I realize this has been discussed in the not too distant past, but this may
be a little different situation. I realize some labs are recycling formalin
to put on their tissue processors
