[Histonet] RE: Dako CSAII vs Elite ABC method, which is more sensitive?

[C.M. van der Loos]

   Hi Kelly,

   When it comes the question which of the two techniques is more
   sensitive I can predict that very certainly the CSA II kit will beat
   the Elite ABC method for. It's just a matter of choices what do you
   prefer and what is technically possible. Personally, I use the CSA II
   kit as my last resort in case the signal with other
   detection techniques is too weak:

   Start using the Elite ABC kit (or EnVision, or other "simple"
   detection system) and titrate your primary with appropriate
   pretreatment over a wide range at a proven positive control. If it
   works fine, you're done. If the signal is too weak, testing with the
   CSA II kit will be step 2. Again, perform a titration experiment over
   a wide range at the same positive control tissue.

   You should also consider that CSA II kit signal is less crisp than
   with other IHC detection systems. Usually this isn't too disturbing.
   The dotty appearance of the reaction product is due to the tyramide
   reaction and can therefore not be improved.

   Hope this helps.

   Chris van der Loos, PhD

   Dept. of Pathology M2-230

   Academical Medical Center

   Meibergdreef 9

   NL-1105 AZ Amsterdam, The Netherlands


   ----- Original Message -----
                                                                 From 
   Kelly D Mcqueeney <kelly.mcqueeney <@t> bms.com>
                                                                 Date 
   Mon, 21 Mar 2005 16:24:59 -0500
                                                                   To 
   histonet <@t> lists.utsouthwestern.edu
                                                              Subject 
   [Histonet] Dako CSAII vs Elite ABC method, which is more sensitive?

   I have been using Elite ABC kit for c-fos IHC in brain. We are getting
   pretty good staining and want to improve sensitivity. I compared the
   Elite  ABC  kit,  Dako's  CSA  tyramide  amplification kit, and Dako's
   Envison
   + kit. The sections are slide-mounted, 20 micron (I increased Dako's
   incubation times to 45 minutes). Dako claims that the tyramide and
   Envision kit are much more sensitive than Elite ABC. I have used the
   tyramide  system  in  the  past  and  was  really  impressed  with the
   increased
   signal. Unfortuantely, Dako's CSA and Envision kit exhibit very weak
   staining and the Elite ABC kit exhibits dark and specific staining in
   the  brain. Has anyone else noticed a change in either product? Should
   I
   order HRP-conjugated c-fos and amplify the signal? Any suggestions
   (besides floating sections)?
   Method: Quench w/Dako's H2O2, block 1 hour 3% BSA in PBT, c-fos O/N,
   wash buffer is PBS +! 0.01% Tw