Eosin is an acid, which has a selective affinity for the cellular cytoplasm (plant or animal); it is preferably attached to the basic molecules and can replace the carmine dye for the preparations. It is often used with hematoxylin, which stains nuclei well.

Eosin is therefore widely used as a dye for laboratory microscopy, to stain the cytoplasm of cells, collagen, muscle fibers, lymphocytes and bacteria.

A class of granulocytes, the eosinophils, whose number increases during allergies and certain parasitoses, derive their name from this dye.

There are several types of eosin and eosin Y (yellowish eosin) is used as a counterstain for hematoxylin in the H & E staining method (Hematoxylin and Eosin).

Eosin Y comes in 2 forms: aqueous solution or alcoholic solution. We propose these 2 forms of solutions with different concentrations from 0.2 to 2%.