[Histonet] controls for immunos and special stains

[Galbraith, Joe]

Julie:

You are required by CAP to run negative controls for immunos that are specific for the species of the primary antibody AND for EACH pretreatment utilized.  There are even some rumblings about isotype specific controls as well but no specific requirement for that as yet to my knowledge.  Naturally you must have a positive control as well.  Our positive controls are on the same slide as the patient tissue section.  We run positive controls that contain elements that stain and don't stain with the primary antibody.  The negative controls are patient tissue sections cut onto separate slides and stained (hopefully negative) with species specific immunoglobulins using each pretreatment method.  In a worst case scenario there will be one negative control for each test slide run.

Ideally your special stain positive controls should contain elements that stain and elements that do not stain.  These should also be 'same slide' controls when possible.  The elements of your positive control that are known to NOT stain could act as a negative control.  Of course the best negative control, if you can find one, would be the same tissue element (ie the same tumor type for example) where one piece was known to have a positive reaction and another piece was known to be negative.

We will often include a normal and abnormal tissue in the on-slide control as well.  For example, a piece of normal lymph node and a piece of lymphoma lymph node for a Bcl-2 control.  This approach provides a nice contrast when there are elements that stain in normal as well as abnormal tissue.

Best wishes,

Joe Galbraith 

-----Original Message-----
From: histonet-bounces <@t> lists.utsouthwestern.edu
[mailto:histonet-bounces <@t> lists.utsouthwestern.edu]On Behalf Of
Julie.Sanders <@t> med.va.gov
Sent: Tuesday, July 27, 2004 12:31 PM
To: histonet <@t> lists.utsouthwestern.edu
Subject: [Histonet] controls for immunos and special stains


I am having a "discussion" with our lab chief concerning the use of controls
with special stain and immunos.  He insists that I run a negative control
with special stains and a "known negative" control for immunos.  Currently
we run only a positive control for specials and a postive control and
negative patient for immunos.
Thoughts and/or protocols would be more than welcome!

Thanks,
Julie
Julie Sanders
Supervisor, Anatomic Pathology
VAMC, Cincinnati, Ohio