As cells mature, from the most immature or blast cell to the final mature stage, they undergo numerous biochemical, structural and metabolic changes. The cytologic features of cells, as observed on Wright's stained peripheral blood and bone marrow smears, reflect such biochemical and structural developments. The general features of cell differentiation are common to most blood cells. Immature cells have delicate, fine nuclear chromatin which gradually becomes coarsely clumped or condensed. The nuclear shape which is initially round or oval may become uniquely confirgured as in myeloid cells.
Mitotic competence is lost as cells differentiate.