Liu’s Stain is modified from the Romanowsky stain technique. Staining of cells involves physical adsorption and chemical affinity which allows stain to penetrate and remain within cells. Because each cell and its components are different in chemical composition, their affinity to acid stain (Eosin) and alkaline stain (Methylene blue) of this kit varies significantly. After staining the smear with the Liu’s Stain, different types of cells will appear in different colors. Consequently, one can identify cells based on their stain color, shape and other physical characteristics.