The branch of science concerned with the identification and distribution of the chemical constituents of tissues by means of stains, indicators, and microscopy.

The standard stains are haematoxylin and eosin, but many others are employed at Pacific Rim Pathology. The use of haematoxylin and eosin-stained slides to provide specific diagnoses based on morphology is considered to be the core skill of anatomic pathology.

The science of staining tissues sections is called histochemistry.