1, reticulocyte count (RC): It is a very economical and simple item, and the RC test can be requested routinely for various anemic diseases to determine whether the anemic disease is proliferative anemia or hypoproliferative anemia, or proliferative normal anemia by the level of RC. 2.Acid hemolysis test (Ham test): It is a simple diagnostic method for paroxysmal sleep hemoglobinuria (PNH). To confirm the diagnosis of PNH, this test needs to be performed in a standardized manner, with positive control, and more than two positive tests. 3, sucrose hemolysis test: the principle of action is similar to acid hemolysis, positive can be seen in PNH, autoimmune hemolysis, hereditary spherocytosis and some aplastic anemia may also be positive. It is a simple screening test for PNH. 4, red blood cell permeability fragility test: red blood cell fragility test reflects the size of the resistance of red blood cells, increased fragility is common in hereditary spherocytosis, also seen in severe autoimmune hemolytic anemia. 5, urinary iron-containing heme test (Rous test): chronic intravascular hemolysis renal tubular epithelial cells can break down free hemoglobin into iron-containing heme, which is deposited in the epithelial cells and reacts positively in the Prussian blue reaction. This test negative can not completely exclude chronic intravascular hemolysis. 6. Anti-human globulin test (Coombs test) and fractionation test: an old test for irregular antibodies in the serum, autoimmune hemolytic anemia can show a positive reaction. Its typing test helps to further determine what kind of irregularity is interfering with the production and destruction of red blood cells. 7. Bone marrow mononuclear cell anti-human globulin typing test: The literature reports the existence of a group of diseases in which the bone marrow picture is characterized by red lineage hyperplasia, possibly with a small amount of pathological hematopoiesis, traces of in situ hemolysis, impaired maturation of megakaryocytes or reduced megakaryocytes; clinical manifestations are complete blood cytopenia, reticulocytes, and significant effects of skin-holding hormone therapy; they occur mostly in young and middle-aged women and may have evidence of immunological abnormalities. The clinical manifestations are allogeneic cytopenia, reticulocytes, and significant effects of hormonal therapy. The bone marrow mononuclear cell anti-human globulin typing test is a new test developed for this type of disease, based on the principle that there may be certain antibodies in the bone marrow that may be directed against young red blood cells, reticulocytes, or naïve granulocyte lines. 8, CD55, CD59 test of peripheral blood erythrocytes: this is a modern diagnostic method to confirm the diagnosis of PNH at the molecular level, the principle is that PNH patients do not express or less express CD55 and CD59 on the surface of blood cells, called CD55 or CD59 negative cells, the presence of such cells in large numbers is the molecular cause of severe hemolysis in PNH.