Tissue macroarrays ("microchops") for gene expression analysis

We describe a simple system of tissue arraying with multiple tissue fragmen ts obtained with a biopsy punch from selected areas of paraffin blocks. The new blocks thus constructed allow multiple tissue sections in which the un iform shape of the fragments coupled with a geometrical display and a signi ficant amount of tissue per case allows a dependable, cost-effective way to screen tumors or other kinds of tissues with techniques such as immunohist ochemistry. This system avoids the disadvantages of previous laborious meth ods of tissue arraying, such as expensive equipment and scarce tissue sampl ing, and it can be implemented in any institution with minimal cost and ela boration.