Nazlia,

We've had great success using a mouse anti rat CD31 sold by Serotec.  The
catalog number is MCA1334G, and their phone number is 1-800-265-7376 or
+44(0)1865 852700  serotec@serotec.co.uk.

Our best results were obtained using ethanol fixed rat tissue.  All types of
tissue, normal and diseased, were fixed in 70%ethanol for 2-3 days at 4C.
After this fixation period, the tissues were run on a tissue processor set
with an alcohol program, starting with 70% - 95 - 100 - xylene, etc.  We did
not need any antigen retrieval steps and used a standard avidin-biotin
detection.  The CD31 antibody was used at 1/100 and make sure to use a
secondary that is absorbed against rat.  We were very pleased with the
results and the morphology was good.  I didn't do much of a workup with
formalin fixed tissues, since the ethanol worked so well and the protocol
was straight forward.  We also have used a rat anti mouse CD31 from
Pharmingen, number 01951D, with the same fixation procedure with excellent
results.

Hope any of this information is useful.  If you need more specifics, let me
know.

Tim Coskran
Pfizer