Fig. 2

a The osmotic fragility test. The inside of the broken line is hemolysis in the normal range, and the solid line shows the degree of hemolysis of this patient. The patient’s red blood cells showed a degree of hemolysis within the normal range in both fresh and incubated red blood cells. b The test tubes of No. 1 to  3 were patient's group with patient's red blood cells and No. 4 to 6 test tubes were control group with normal red blood cells. Paroxysmal nocturnal hemoglobinuria (PNH) shows hemolysis with a mixture of acidified serum and patient erythrocytes (the No.2 test tube is positive), but inactivated serum and patient erythrocytes do not hemolyze even with acidification (the No. 3 test tube is negative). Present case showed negative response in all No. 1 to 3 test tubes