Several drepanocytes are also seen in this field of a blood smear from a sickle cell patient. Sickle cells may have either the appearance shown in the photomicrograph at S, with sharp points, or may appear with more blunted ends, as in D. Homozygous sickle cell anemia is the condition in which drepanocytes are seen; however other tests are needed to make the diagnosis of sickle cell anemia. Most sickled cells can revert back to the discoid shape when oxygenated. About 10% of sickled cells are unable to revert back to their original shape after repeated sickling episodes.