Routine (H&E) staining is the corner stone of tissue-based diagnosis. The process stains thin tissue sections so that pathologists can visualize tissue morphology. The process uses a haematoxylin dye to stain cell nuclei (and other parts) blue and an eosin dye to stain other structures pink or red. Properly applied, this technique provides exceptional detail of tissue structure and the makeup of the cells. This detail is required for tissue-based diagnosis, particularly in the detection and classification of cancer. Special stains use a variety of dyes and techniques to stain particular tissues, structures or pathogens (such as bacteria) to assist pathologists with tissue-based diagnosis.