This table represents cells of red bone marrow after azure II and eosin stain. One may see typical morphological changes of the hematopoietic cells during their development.

Red blood cell precursors transform into mature formed elements with the following changes:

• a decrease of cell size
• a decrease of nucleus size, as well as its condensation and removal from cells
• a decrease of RNA content in the cytoplasm with simultaneous hemoglobin accumulation resulting in a shift of cytoplasmic staining from basophilic to oxyphilic

When granulocyte precursors are being formed and differentiated, they show:

• a decrease of cell size
• transformation of nucleus shape (rounded to segmented)
• accumulation of granules in the cytoplasm (first of all, non-specific azurophilic granules appear followed by specific neutrophilic, eosinophilic, or basophilic ones)

The development of lymphocyte precursors in red bone marrow is accompanied by:

• a decrease of cell size
• a decrease of cytoplasmic volume
• a decrease of nucleus size and an increase of its density

Monocyte precursor differentiation into mature types means:

• lightening of cytoplasmic basophilic staining
• accumulation of azurophilic granules in the cytoplasm
• originally rounded nuclei become bean-shaped

Platelets are produced through cytoplasm fragmentation in giant bone marrow cells referred as megakaryocytes. The megakaryocytes are derived from their precursors via all of the following:

• an increase of cell size
• an advance in splitting of nuclei
• enhancement of basophilic staining in the cytoplasm
• when its platelets are released, the resulting cell retains a lobular nucleus surrounded by a thin rim of cytoplasm (residual megakaryocyte)