To study tissue samples from multiple patients, researchers use tissue microarrays (TMAs), a technology in which hundreds of tissue cores are arranged on a single glass slide for analysis by immunostaining or in situ hybridization. TMAs typically are prepared by punching cores out of paraffin-embedded tissue blocks and relocating them in specific positions in a new block, which is then sliced to produce dozens of slides.
But this method, widely used for tumor analysis, has shortcomings, including potential sample loss during core retrieval due to variations in tissue depth and quality, and low feature density due to the massive amounts of scaffolding material needed to hold the samples in place.
Cutting edge matrix assembly (CEMA), an enhanced microarray-fabrication approach recently devised by Matthew LeBaron and colleagues at Georgetown University,1 addresses both of these problems. CEMA minimizes tissue loss by trimming the samples to a uniform thickness and eliminates the...