Hi, Our CD4 works very well. It is the novocastra clone pretreated with edta
stream pretreatment. for 25 minutes. 60 minutes in antibody, evision
detection system(mouse from dako) 30 minutes. dab 8 minutes. This is done on
a dako autostainer. one improtant note with the CD4 from novocastra DO NOT
use a H2O2 block it will interfere with the results go right from streamer to
the primary step. hope this helps

"Stock, Rachel" wrote:

> Hello Histonetters!
> I've been asked to work out CD4 staining on formalin-fixed, paraffin
> embedded lymph node. Naturally, the first thing I did was to look at the
> Histonet Archives. I have tried both the Novocasta and Serotec CD4
> primaries, which are the same clone. HIER in the microwave with EDTA pH8
> gives the strongest signal, but the staining looks "muddy" and the
> background is high.  I have tried several different variations, including
> avidin-biotin blocking, serum block, biotinylated-anti-mouse secondary,
> etc., and still no improvement. Our lab uses a Ventana Biotech automated
> stainer for routine IHC, and the ideal situation would utilize the
> accompanying Ventana kit reagents, but I have also tried Vector reagents,
> staining manualy and with our DAKO autostainer.
>
> Any suggestions? Anyone with a working protocol?
> Many thanks in advance,
>
> Rachel Stock, HTL(ASCP)
> UMass Medical Center
> Worcester, MA