[Histonet] RE: PCNA versus Ki67

[C.M. van der Loos]

   Dear Brett,

   As  been said before, you will find more positive cells with PCNA than
   with  Ki67.  As far as I know is due to a different half-life of these
   antigens.  That's  the  reason why also cells in the G0 phase might be
   PCNA positive.

   But,   if you're   in   doubt   whether   to  use  PCNA  or  Ki67, why
   not visualizing  both  of them  in  double  staining? Since you have a
   mouse  anti-PCNA  and  rabbit anti-Ki67 (LabVision/Neomarkers) life is
   simple  here.  Prepare  a  cocktail  of these primaries (appropriately
   diluted    of    course).    Than,   prepare   a   1:1   cocktail   of
   PowerVision-anti-rabbit/AP        and       PowerVision-anti-mouse/HRP
   (ImmunoVision) and  incubate  for  60 min. Develop AP and HRP activity
   respectively  in blue  (Vector Blue or home-made Fast Blue BB) and red
   (AEC or Vector NovaRed). Done!!!

   Cheers,

   Chris van der Loos, PhD
   Dept. of Pathology
   Academic Medical Center M2-230
   Meibergdreef 9
   NL-1105 AZ Amsterdam
   The Netherlands

   phone:  +31 20 5665631
   fax:    +31 20 6960389

   Date: Mon, 24 Oct 2005 17:44:40 -0400
   From: "Connolly, Brett M" <brett_connolly <@t> merck.com>
   Subject: [Histonet] PCNA versus Ki67
   To: histonet <@t> lists.utsouthwestern.edu
   I  have  been  a big proponent of using Ki67 instead of PCNA as a more
   accurate
   proliferation  marker  after  reading that PCNA may in fact carry over
   into G0.
   Recently, some of my colleagues have been clamoring for PCNA.
   I'd be interested to hear which marker other labs are using.
   Thanks,
   Brett
   Brett M. Connolly, Ph.D.
   Merck & Co., Inc.
   MRL, Imaging Research
   WP-44K
   PO Box 4
   West Point, PA 19486
   PH 215-652-2501
   fax. 215-993-6803