Giemsa stain

The Giemsa stain is a modified Romanowsky stain for methanol- fixed bone marrow and blood smears and cytological specimens ( eg, urine sediment, sputum ), which serves to distinguish different cell types from each other. It was introduced by the Hamburg chemist Gustav Giemsa in 1904 and named after him.

The Giemsa solution is a mixture of the dyes of Azure A Eosinat, Azure B Eosinat, methylene blue, and methylene blue Eosinat chloride in methanol with glycerol as a stabilizer. It is therefore also called Azur -eosin methylene blue solution.

The intensity of the coloration depends upon the exact composition of the Giemsa solution. Nuclei appear in stained smears by a complex formation of the dyes with the DNA purple. The cytoplasm is usually represented bluish. Parasites or protozoan nuclei also appear bright red. However, the staining result can have significant differences. It is influenced among other things by the pH of the solution and the buffer solution, the buffer substances, dyeing time and the type of fixation.