[Histonet] AFB Contamination

Lee & Peggy Wenk lpwenk <@t> sbcglobal.net
Tue Apr 24 15:27:16 CDT 2007

Send samples of water (tap, d. water, flotation bath, etc) to the
microbiology lab, and have them do cultures on it. These are a possible
source of bacteria. Some parts of the US have non-pathogenic acid fast
bacteria in their water supply (OK to drink, but a concern in labs for false
positives). In our lab (Michigan), a couple of years after we moved into a
new lab area, we found gram negative water in the d. water. They had hooked
up the d. water lines wrong, and it took us months before they were able to
eliminate all the bacteria.

Also, what is your control slide? Any chance it's a smear? Bacteria could be
wafting off from that. Other people on Histonet have also commented that
they have experienced the same phenomena of bacteria coming off the fixed,
processed control slide, when the control is loaded with AFB. 

Peggy A. Wenk, HTL(ASCP)SLS
William Beaumont Hospital
Royal Oak, MI 48073

-----Original Message-----
From: histonet-bounces <@t> lists.utsouthwestern.edu
[mailto:histonet-bounces <@t> lists.utsouthwestern.edu] On Behalf Of
Tracey.Lenek <@t> CLS.ab.ca
Sent: Tuesday, April 24, 2007 4:14 PM
To: histonet <@t> lists.utsouthwestern.edu
Subject: [Histonet] AFB Contamination


We are experiencing transient false positive ZN staining on skin biopies.
Today a slide had clumped AFB over the majority of the slide where no tissue
was present.  Previous to this, only one or two bacilli were noted on the
Has anyone investigated and found a contaminated waterbath or perhaps the
Kinyoun's is the culprit as our  lab reuses both?  Any help would be


CONFIDENTIALITY NOTICE: This e-mail and any files/attachments may contain
confidential, personal and/or privileged information intended for a specific
purpose and recipient. If you are not the intended recipient do not
disclose, copy, retain, distribute, use or modify any of the contents of
this transmission. If you received this transmission in error please notify
me immediately by return e-mail or telephone and destroy the entire
transmission and any copies produced. Thank you. 
Histonet mailing list
Histonet <@t> lists.utsouthwestern.edu

More information about the Histonet mailing list