Introduction

Romanowsky polychromatic dyes are standardly used in hematology and cytology. Various sorts of Romanowsky dyes (Giemsa, May-Gruenwald, Leishman, Wright, Jenner) contain different ratios of methylene bluing reagent used as the cation component (and the reagent-related thiazine dyes, such as azure B) and eosin Y as the anion component. Known Romanowsky effect is created by mutual interaction between cationic and anionic components, and it is being demonstrated by purple color. Staining intensity depends on the azure content, as well as azure to eosin Y ratio, while a few other factors affect the result of staining: working solution pH value and buffer solution, fixation method and dye exposure time.