Atlas of plant and animal histology

Dyes are molecules used to stain the structures of animal and plant tissues, that is, they provide colors to cell structures and extracellular matrix. There are a broad variety of dyes used in histological techniques, and they are selected depending on the sample and the features to be study. Dyes are selected regarding the color they provide, molecular weight, solubility, their affinity to bind and react with tissular molecules.

The structures to be stained and the color the dyes may provide can be guessed from their chemical nature. Regarding the electrical charge, which can be deduced from the molecular composition, dyes are classified into cationic or basic dyes, which stain nuclei and acid carbohydrates, and anionic or basic dyes that stain the cytoplasm and the extracellular matrix. The non-charged dyes can be molecules that stain a variety of structures, liposoluble dyes for staining lipid depots, and mordants that color myelin and nuclei. The size of the dye molecules and their ability to form aggregates is sometimes important because of their difficulty to diffuse through tissues. For example, anionic dyes with different sizes can be selectively used to stain different structures.

Diversity of dyes (modified from Kiernann 2009).

• Bibliography ↷

  • Kiernann JA. (2009). Histologican and histochemical methods. Theory and practice. 4th edition. Scion Published Ltd. ISBN 9789048422

    Llewellyn B. (retrieved: 2022). Stain files. http://stainsfile.info/dyes/dyes.htm