In situ hybridization (ISH) staining is a technique that uses a labeled complementary DNA, RNA or modified nucleic acids strand (i.e., probe) to localize a specific DNA or RNA sequence in a portion or section of tissue. In situ hybridization can be a powerful technique for identifying specific mRNA species within individual cells in tissue sections, providing insights into physiological processes and disease pathogenesis.

Researchers and clinicians have traditionally examined tissue slides stained with H&E, IHC, ISH, fluorescent ISH (FISH), or other methods under a bright-field or a fluorescence microscope. However, as the assays are becoming more complicated and often require locating and counting of hundreds or thousands of cells of specific types in specific types of regions, performing these tasks manually (and accurately) becomes an increasingly difficult task. Accordingly, more and more researchers and clinicians are beginning to employ “digital pathology” solutions that can help them get faster, more accurate, and more reproducible results. Digital pathology systems include slide scanners that can scan tissue slides to produce very high resolution (e.g., 0.5 or 0.275 microns per pixel) digital images of the tissue. Digital pathology systems also include hardware and/or software solutions for automatically processing, viewing, segmenting, analyzing (e.g., scoring) and otherwise managing tissue images or other types of biological specimen images.