Figure 2
The structure of erythrocytes from centrifuged unclotted human blood. Scanning electron micrograph showing the shape change of erythrocytes as a result of the forces of centrifugation at 6000g. Polyhedrocytes were observed with centrifugation of blood at forces of 1000g or greater, but not at lower forces. From the weight of a single erythrocyte of ∼1 pN or 10−7 dyn force applied to half of its surface area, the minimal stress required to induce polyhedrocyte formation and tight packing is estimated to be ∼75 to 150 dyn/cm2, well within the range of stress generated by platelets during contraction. Magnification bar = 10 µm.
