Hi Heike-

Just thought I would let you know that in my experience with MIB-1 (KI-67
clone) there was a tendency toward the loss of antigenicity in cut slides
that had been stored for over 4 months.  We noticed a significant reduction
(like no staining vs lots of staining) when we compared sections that had
been stored for 4 months to fresh cut sections.  This was all formalin
fixed paraffin embedded tissue.  Also, we used a much more aggressive
antigen retrieval protocol. I believe it was 4X 5 minutes in the microwave
in 10mM citrate pH 6.  Another thing that you might consider is the lapse
between the time that the sample was taken and the time it is placed into
fixative.



Margaret









Heike Grabsch <h.grabsch@uni-koeln.de> on 03/05/99 12:14:36 AM

To:   histonet@pathology.swmed.edu
cc:    (bcc: Margaret Gondo/GeneMedicine)
Subject:  MIB1 + bone marrow




Histonetters!
anybody out there doing immunohistochemistry on bone marrow sections with
MIB 1? We get no staining so far. However, I have to admit that in
Germany the routine fixation for bone marrow biopsies contains a
combination of glutaraldehyde, formaldehyde and other ingredients. So, I
currently assume it is the glutaraldehyde which destroys the MIB1
epitope.
But may be, there are some suggestions aout there? some special
pre-treatment? We use a pressure cooker (5 min) in citrate buffer at the
moment and a straeptavidin-biotin-hrp- detection system.
thanks for your help
Heike Grabsch, Germany