Hi all.

I wrote this manual (below) a couple of years ago. Maybe it is of some help.

Kenneth



Preparation of Multi Tissue Blocks (MTB).


MTB could be used for simultaneous staining and studies of different types
of tissues, tumours or processing protocols. In testings of new antibodies
and alternative staining protocols they have become extremely useful in our
laboratory, saving both time and reagents. The possibility to, in one
section/staining, get an overview of i.e. various tumour grades and stages
also makes the evaluation more reliable and comparisons easier to perform.
Different preparation techniques of MTB has been described in the
literature recently. The technique described here is slightly modified from
these protocols.



*	Select tissue areas of interest from archival paraffin embedded
	material.


*	The selected areas are removed from the blocks by pressing a biopsy
	punch perpendicular to the tissue surface. If the biopsy punch is
dipped 	in xylene and simultaneously rotated while pressed into the block,
this 	proceedure is most often smoothly performed.

	The tissue cylinder is peeled out by inserting a wooden stick into
the 	biopsy punch, through the handle, and gently pressing the cylinder
out. 	If the tissue cylinder doesn't come out smoothly this way, freeze
the 	biopsy punch, with the tissue cylinder still inside, by spraying
	cryo spray onto it for a few seconds, and the try pressing again.

	The biopsy punch must be hollow in order to peel out the tissue
	cylinder. If that is not the case the biopsy punch has to be
modified.
	The diameter of the biopsy punch is dependent on the number of
	samples to be included in the respective MTB. We are using  4mm
	when the total number are maximized to 12. If the number of samples
	per MTB exceeds 12 we are using  3mm.


*	The tissue cylinders are attached to an embedding mould by first
	touching the cylinder ends to a hot plate, superficially melting
the 	paraffin, and then applying them, vertically, to the bottom of the
	embedding mould. An alternative is to heat the embedding mould
	instead of the tissue cylinder ends.

	Carefully note the positions for the tissue cylinders in order to
identify 	the  respective sample.


*	When the tissue cylinders are firmly attached to the embedding
mould, 	apply the cassette and fill the mould with paraffin.

Kenneth Wester, Ph.D.                  	phone:  +46 (0)18 611 02 06

Dept. of Genetics & Pathology		fax:    +46 (0)18 471 3432
The Rudbeck laboratory
Uppsala University
Dag Hammarskjöldsväg 20
S-752 37 Uppsala, Sweden