Basophils develop from the multipotential myeloid stem cell (CFU-GEMM) which differentiates into basophil progenitor cells (CFU-Baso).
Basophilic myeloblasts are produced from progenitor cells (CFU-Baso) under the influence of cytokines. The basophilic myeloblast matures into a basophilic promyelocyte. These cells cannot be distinguished from cells at the same stage in other granulocyte lineages.
Basophilic myelocyte is the first recognizable precursor of basophils.
Large cells (18 to 20 µm diameter)
Round, oval, or indented nucleus (50% of cell) with a coarser, granular pattern of chromatin
Cytoplasm is pale blue
Very basophilic, specific granules begin to accumulate
Last cell type capable of mitosis
It is difficult to find developing basophils because they account for less than 0.5% of granulocytes.