A protein atlas has been created (www.proteinatlas.org) to show the expression and localization of proteins in a large variety of normal human tissues and cancer cells. The data is presented as high resolution images representing immunohistochemically stained tissue sections. Available proteins (genes) can be reached through a specific search (by gene/protein name/id or classification, such as kinase or protease) or by browsing the individual chromosomes.

The protein atlas contains histological images from sections of human tissue. These images are equivalent to what is seen in a microscope when examining sections of tissue on glass slides. Each antibody in the database has been used for immunohistochemical staining of both normal and cancer tissue. The immunohistochemical protocols used result in a brown-black staining, localized where an antibody has bound to its corresponding antigen. The tissue section is furthermore histochemically stained with hematoxylin to enable visualization of microscopical features. Hematoxylin staining is unspecific and results in a blue coloring of both cells and extracellular material.

Tissue microarrays have been used to enable immunohistochemical staining of a large number and variety of normal and cancerous tissues. The design of used tissue microarrays include samples of 48 different normal tissue types and 20 different types of cancer. For each antibody, protein expression patterns in normal tissue can be viewed as triplicates from 144 different individuals and in cancer tissue viewed as duplicates from 216 different patients