Tissue macroarrays ("microchops") for gene expression analysis.

We describe a simple system of tissue arraying with multiple tissue fragments obtained with a biopsy punch from selected areas of paraffin blocks. The new blocks thus constructed allow multiple tissue sections in which the uniform shape of the fragments coupled with a geometrical display and a significant amount of tissue per case allows a dependable, cost-effective way to screen tumors or other kinds of tissues with techniques such as immunohistochemistry. This system avoids the disadvantages of previous laborious methods of tissue arraying, such as expensive equipment and scarce tissue sampling, and it can be implemented in any institution with minimal cost and elaboration.