RE: ABC and brown color on the slide
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From: | "Louise Taylor" <louiset@mail.saimr.wits.ac.za> (by way of histonet) |
To: | histonet@histosearch.com |
Reply-To: | |
Content-Type: | text/plain; charset="us-ascii" |
Dear Tibor and friend
Three thoughts come to mind
1. This might be a washing problem. You do not mention how you went about
washing your slides: rinsing in a jet of PBS from a squishy bottle, in a
coplin jar or in a staining dish of buffer with agitation. From personal
experiece I have found that washing in a dish with agitation to be the
better method, especially when soemthing like a PAN pen is used to isolate
the tissue. This seems to create a "well" in which the of the reagents tend
to stick around (due to their suface tension in a confined space - I think).
2. Check that the blocking serum is not cross reacting with that of the
seconadry biotinylated antibody (in the kit). We generally use the same
species ie if the secondary is raised in goat, then we block in goat serum.
3. Check the dilution of the Primary (unless you are using a pre-dilute)
Hope things work out - know the feeling
Best Regards
Louise Taylor
SAIMR
Johannesburg
South Africa
-----Original Message-----
From: Tibor [mailto:tibor@home.se]
Sent: 01 February 2000 07:21
To: histonet@pathology.swmed.edu
Subject: ABC and brown color on the slide
Hi!
I and my friend (both students) had to try out CK 5/6 at the hospital
where we will do our special project before finishing the last term at
university.
We used the ABC technic with microwave antigen retrieval.
The procedure was like this:
We dewaxed the slides in xyleen for 2x10 minutes, in abs alc for 2x5
minutes in 95% alc for 2x5 minutes and short time in 70% alc to
distilled water.
Before retrieval we blocked the endogenous peroxidase with 0.5 ml H2O2
in 50 ml Aq Dest in 30 minutes.
After retrieval in citrate buffer pH 6.0 we washed in PBS (pH 7.4) in 5
minutes
then we blocked with normal rabbit serum (1:5 in PBS) in 40 minutes.
The primary antibody (monoclonal from Boeringer Mannheim Biochemica
cat. no. 1273396) was diluted in 1:20 and we incubated ON in the
fridge.
The day after we washed in PBS and applied the secondary biotinated
antibody (1:200 in PBS) and incubated at RM in 30 min.
The ABC was prepared taking 5 ml PBS 1 drop A and 1 drop B (from the
kit, sorry I forget to check which kit). We let the mixture stay on RT
in 30-60 minutes.
DAB was added (first we washed with PBS) and we developed in 10
minutes. After this time we washed i tap water in 5 minutes and
counter stained in Mayer's hematoxylin in 5 minutes and differentiated
with 1% HCl in alcohol (this has a swedish name "saltsur sprit") and
then we did the bluing in tap water.
After this we dehydrated in 70% alc, 90% alc, 100% for 2x5 minutes and
in
Xyleen 2x5 minutes and mounted in Mountex.
When our pathologist compared our slides with the ones done on Ventana
he found that the machine had better color (it uses Zn too).
Now, our problem is that brown color on the slide around the tissue
(according to our pathologist we didn't had background in the tissue
itself). We used PAN PEN, and we can see how this brown color appears
within the mark done with the pen. It's looking ugly...
I hope that I've provided enough information to get some suggestions
what to do. We are totally new and we never did this before.
Please, what we should do to get rid of that brown color on our slide?
In march we have to do our project and then we are going to do much
more slides. It wouldn't be fun having all of them brown around the
tissue.
My friend and I would be very pleased to get any suggestions.
Thanks in advance!
======================
Tibor Ric and Juan Paredes
students from Sweden (The University of Karlstad)
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