Ian,
As long as the tissues were fixed for equivalent times and be equal in
thickness I can't see a problem with the IPXs. I use composite blocks of
liver, skin and gut for my keratin controls.

Regards,
Tony Henwood JP, BappSc, GradDipSysAnalys, CT(ASC)
Laboratory Manager
The Children's Hospital at  Westmead,
Locked Bag 4001, Westmead, 2145, AUSTRALIA.
Tel: (02) 9845 3306
Fax: (02) 9845 3318

>>> "Dr. Ian Montgomery." <ian.montgomery@bio.gla.ac.uk>
1/March/2001 01:08am >>>
         In the past and mostly for undergraduate teaching, I've prepared 
composite blocks of various tissues. You know the sort of thing, pieces
of 
kidney, liver, muscle, gut, lung and brain sandwiched together and
stained 
using a variety of techniques. Works well, although trichromes can be a
bit 
of a bugger when differentiating. For teaching very handy as the
students 
can move from tissue to tissue without changing slide when comparing
the 
structures.
         Now, my latest problem and hopefully easily solved. Has anyone 
tried this sort of thing for IHC. I have 9 pieces of tissue from a very 
large number of animals which if I can prepare composites blocks off
would 
make my life a lot easier. Does IHC throw up any cheeky wee problems
which 
I've not thought about, eg. tissue dependent retrieval, or is it pretty 
straight forward.
          Comments very welcome, sorry I can't be cloned, grow extra
hands 
or work double, triple shifts.
Ian.

Dr. Ian Montgomery,
West Medical Building,
University of Glasgow,
Glasgow,
G12 8QQ.
Tel: 0141 339 8855.  Extn:6602.
Fax: 0141 330 2923
e-mail: ian.montgomery@bio.gla.ac.uk