Basophils develop from the multipotential myeloid stem cell (CFU-GEMM) which differentiates into basophilic progenitor cells (CFU-Ba).
Basophilic myeloblasts are produced directly from progenitor cells (CFU-Ba) 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. (See MH034B Neutrophil Development for these earlier stages.)
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 capable of mitosis
It is difficult to find developing basophils because they account for less than 0.5% of granulocytes.