When changing instruments you are validating the instrument, not the test. For each antibody you just need to run parallel tests in each instrument showing equivalence.
However, if you change the instrument and ALSO change the antibody and/or detection system, Antigen retrieval, etc, then you need to revalidate the test. For most antibodies (Class I FDA exempt, ancillary tests) that involves 5-10 positive and negative cases. A small tissue array can suffice. You should do reproducibility tests for a few antibodies - 5-10 identical slides on one run, 5-10 identical slides on 5-10 runs. When changing Class II antibodies (ER, PR, Her2) and/or their detection systems you will need to run more extensive test. As Liz says, 40 positive, 40 negative. Again, a tissue array is great for that. Changing instruments these days is a big deal when a vendor ties you to their reagents. Tim Morken Supervisor, Histology, IPOX UCSF Medical Center San Francisco, CA, USA -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Liz Chlipala Sent: Tuesday, February 08, 2011 3:20 PM To: Weems, Joyce; Joe Nocito; Histonet Subject: RE: [Histonet] IHC validation Nope that's the recommendation for everything, in the paper they state additional development is required for prognostic markers. Once you have validated an antibody it only requires 3 tissues when you get a new lot number: 1 strong positive, 1 weak to moderate positive and 1 negative. >From how I read the article its 25 tissues and then 3 tissues, it does not talk about slides so it is possible to put multiple tissues on one slide. Again these are just recommendations; I do not think that there is a set standard yet. Liz Elizabeth A. Chlipala, BS, HTL(ASCP)QIHC Manager Premier Laboratory, LLC PO Box 18592 Boulder, Colorado 80308 office (303) 682-3949 fax (303) 682-9060 www.premierlab.com Ship to Address: 1567 Skyway Drive, Unit E Longmont, Colorado 80504 -----Original Message----- From: Weems, Joyce [mailto:[email protected]] Sent: Tuesday, February 08, 2011 4:13 PM To: Liz Chlipala; Joe Nocito; Histonet Subject: RE: [Histonet] IHC validation But that is for receptors, correct? Do you do that for everything? Thanks, j -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Liz Chlipala Sent: Tuesday, February 08, 2011 17:58 To: Joe Nocito; Histonet Subject: RE: [Histonet] IHC validation Joe If you are following the recommendations from the CAP paper on IHC standardization then it would be 25 tissues (10 strong positive, 10 weak to moderate positive and 5 negative). Liz Elizabeth A. Chlipala, BS, HTL(ASCP)QIHC Manager Premier Laboratory, LLC PO Box 18592 Boulder, Colorado 80308 office (303) 682-3949 fax (303) 682-9060 www.premierlab.com Ship to Address: 1567 Skyway Drive, Unit E Longmont, Colorado 80504 -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Joe Nocito Sent: Tuesday, February 08, 2011 3:44 PM To: Histonet Subject: [Histonet] IHC validation Greetings Histoland, I need some help. We are about to switch IHC machines from the Richard-Allen Axiom to the Ventana Benchmark Ultra. How many slides, per antibody, do you run for the validation study? We have over 100 primary antibodies. Normally, when we work up a new antibody, we start with a titer. Once that is established, we run 10 cases to check for specificity. Hopefully we can obtain cases that are really positive, some weakly positive and some flat out negative. Once that is completed, we run 10 different tissue types to check for any unexpected cross-reactivity. The ultra holds 30 slides and we are receiving two machines. If we run 10 slides/antibody, that's going to take a while, not to mention the number of detection kits that will be used. Do you think 5 slides/antibody is sufficient? I emailed CAP last week for their take and they never returned my email (I told my medical director to hold their check for the year and see how fast they respond to that). Ah oh, don't go down that road Joe, it's unhealthy. What are your thoughts? Thanks Joe (JTT) _______________________________________________ Histonet mailing list [email protected] http://lists.utsouthwestern.edu/mailman/listinfo/histonet _______________________________________________ Histonet mailing list [email protected] http://lists.utsouthwestern.edu/mailman/listinfo/histonet Confidentiality Notice: This e-mail, including any attachments is the property of Catholic Health East and is intended for the sole use of the intended recipient(s). It may contain information that is privileged and confidential. Any unauthorized review, use, disclosure, or distribution is prohibited. If you are not the intended recipient, please delete this message, and reply to the sender regarding the error in a separate email. _______________________________________________ Histonet mailing list [email protected] http://lists.utsouthwestern.edu/mailman/listinfo/histonet _______________________________________________ Histonet mailing list [email protected] http://lists.utsouthwestern.edu/mailman/listinfo/histonet
