The basophilic normoblast is slightly smaller in size than the pronormoblast. The chromatin is a bit more condensed, while just beginning to clump. At this stage, the nucleoli will have closed completely. The absence of nucleoli is the major feature that distinguishes a basophilic normoblast from a pronormoblast. The midnight-blue, velvety-look of the cytoplasm is still very prominent, which makes this cytoplasm morphology indistinguishable from that found in a pronormoblast. As a basophilic normoblast continues to mature, the overall cell size will decrease and the chromatin will condense. The cytoplasm will gradually begin to lighten as globin chain synthesis begins.
The first image to the right shows three early basophilic normoblasts (red arrows), including one that is binucleate. Notice the grainy, reticular texture of the chromatin. The chromatin has clumped where the nucleoli have closed. The nuclear pores are more prominent. The deep basophilia is starting to lighten in the golgi area, which is normal as globin synthesis progresses. Binucleated red blood cells are normal so long as the two nuclei are of even size. They can be observed most commonly in bone marrows with increased erythroid production.
The second image shows a group of basophilic normoblasts (red arrow) maturing toward the polychromatophilic normoblast stage. Notice that the size of the cell continues to shrink. The chromatin is becoming more condensed. Also notice that the cytoplasm remains quite basophilic.