[Histonet] FITC on Ventana Ultra

Morken, Tim Timothy.Morken <@t> ucsfmedctr.org
Fri Aug 27 11:52:43 CDT 2010

Part of the Ventana response was "Many customers, however have expressed that they would rather utilize the slide drawer for another patient slide, rather than running the fitc negative."

I hope the customers come to understand that the negative control is necessary, not just an option.

Also, it has come to light that it is difficult to run lot comparison tests on some automated instruments as CAP is now requiring. From Ventana the information I have gotten is that the customer has to "trick" the system to be able to test two lots in one run. Two lots of the same antibody can be used on one run, but the system will use the oldest lot first, then switch to the new lot when the old lot runs out. So to do a lot comparison the customer must arrange to use the last test from the old lot on one slide and then assume the system will switch to the new lot for the other slide. Hopefully it works.

I don't use Ventana but am interested because we are looking at the system, plus I am giving a validation workshop at NSH and one of the most common questions now is how to do a lot comparison test on an automated system. I welcome any other information on that process on any system.

Tim Morken
Supervisor, Histology, IPOX
UCSF Medical Center
San Francisco, CA, USA

-----Original Message-----
From: histonet-bounces <@t> lists.utsouthwestern.edu [mailto:histonet-bounces <@t> lists.utsouthwestern.edu] On Behalf Of Nita Searcy
Sent: Friday, August 27, 2010 7:30 AM
To: histonet <@t> lists.utsouthwestern.edu
Subject: [Histonet] FITC on Ventana Ultra

Any users out there that have had A CAP inspector question negative control on the instrument? In regard to CAP question ANP.21850 in which the notes state, "A negative reagent control in which the patient tissue is processed in an identical manner to the test specimen but with the primary antibody omitted must be performed for each patient test specimen?"

Below is the response from Ventana regarding "negatives" I am curios if CAP accepts these methods??

In regards to the question below about running a negative control fitc, there are two ways to accomplish this.

1) There is not currently a place in the protocol to select a fitc negative. We can still be compliant by ensuring the negative slide is treated the same as the patient. The only reagent the patient slide is exposed to, besides the fitc antibody, is reaction buffer. Running a negative can be accomplished by applying reaction buffer to the slide and letting it incubate for the same amount of time. Next, it is important to ensure both slides are coverslipped in the came mounting media.
2) The second method is to utilize internal negatives that are already present within the patient tissue. However, this is difficult when running Fitc antibodies such as IgG, IgM, etc.
We are looking into adding this addition into the software. Many customers, however have expressed that they would rather utilize the slide drawer for another patient slide, rather than running the fitc negative.

Am interested in your comments.

Nita Searcy, HT/HTL (ASCP)
Scott and White Hospital
Division Manager, Anatomic Pathology
2401 S. 31st. Street
Temple, Texas, 76502
nsearcy <@t> swmail.sw.org


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