During cell maturation considerable changes appear in the cytoplasm as well. They are reflected in the change in its ability of reacting with dyes, the occurrence of granulation, and appearing of new substances.
The loss of basophilic is the main change in the cytoplasm. It is a tendency to bind basic dyes, for example methylene blue. After dying, the cytoplasm has brighter or darker blue color. During maturation the basophilic of the cytoplasm of mature cells (granulocytic, erythrocytic, and thrombocytic series) becomes acidophilic, i.e., stained by acid dyes (red). The other characteristic change in the cytoplasm is the occurrence of granulation in the cells of some lines. In the cells of the myelocytic lineage, granules in less mature cells are rare and non-differentiated. In more mature and completely matured cells granules are more numerous and differentiated in their behavior on stains. Some granules are stained by basic dyes only, so they are dark blue. Therefore, they are called basophil granules, and the leukocytes - basophil leukocytes.
In other granulocytes, granules are stained by acid dyes. They are called acidophil or eosinophil granules, and leukocytes - eosinophil leukocytes.
The third kind of granules stains poorly both by basic and acid dyes. They are faint pink and called neutrophil, and leukocytes containing them - neutrophil leukocytes.
A new ingredient may appear in the cytoplasm during maturation. The best example is hemoglobin in the cells of the erythrocytic lineage.