Iron (Perls) staining of sideroblasts in bone marrow smear (human)

Stain: Perl's stain for iron (Prussian blue). The intense blue stained hemosiderin in the erythroblasts (1) is visible as siderotic granules (pathologic siderosomes). These pathologic siderosomes are sometimes distributed in a circle around the nucleus (ringed sideroblasts). The myeloid cell types (2) are devoid of these siderotic granules. Normal iron particles are pitted from the cells and reutilized by macrophages in the spleen and reticulum cells in the bone marrow. (3) Proerythroblast with blue granules.