To make multitissue blocks I use the method describe by Miller RT which
seems to be easier to handle. Look at Miller, RT:  Multitumor "Sandwich"
Blocks in Immunohistochemistry.  Simplified Method of Preparation and
Practical Uses.  Applied Immunohistochemistry 1(2):156-159, 1993.

Rodney T. Miller is now the Director of Immunohistochemistry at ProPath
Laboratory Inc., 8267 Elmbrook, suite 100, Dallas, Texas 75247-4009,
email: rtmiller@ont.com
You can get a lot of information about the multitissue block and other
ICC-FAQs at http://www.propathlab.com

hope this helps,

Heike Grabsch, Germany