On Wed, 10 Feb 1999 22:40:48 -0800, Heike Grabsch wrote:

>monoclonal from Dako, dilution 1:40, 5 min pressure cooking in citrate
>buffer pH 6.0
>And now, all over sudden, it does not work anymore, only very very faint
>staining. We checked dilutions and even tried antibody "pure". Expiration

1. for some antibodies, icluding the bcl-2 (and even more all the
antibodies from
Novocastra) the cooling phase after cooking has finished, is crucial. Try
to check this
time, it should be at least 20 minutes.

2. Sometimes some kind of hyphae and bacteria grow in the primary antibody,
especially when it is a prediluted one. I remember a similar problem  with
a CD4 from
Novocastra, and after 2 weeks  within a couple of hours it became milky.

			Alexander Nader
			Alexander.Nader@univie.ac.at
			HTTP://members.teleweb.at/anader