Figure 4.

Quantification of biconcave and polyhedral RBCs in the layers of blood clots at varying degrees of contraction. (A) Representative scanning electron micrographs taken in the outer layer (left column), intermediate part (middle column), and center (right column) of a contracted blood clot. The clot outer layer (Ai) contains mostly nondeformed biconcave RBCs (represented in Figure 1Ai) and empty spaces, whereas in the center (Aiii) all cells are compressed (Figure 1Aiv) and there are almost no empty spaces. The intermediate layer (Aii) contains intermediate-shaped RBCs (Figure 1Aii-iii). Fibrin is revealed in the outer layer and intermediate parts only. Scale bars represent 25 μm. (B-C) Dot plots showing a reduction of the absolute number of biconcave RBCs (Bi-iii) and increase of polyhedral RBCs (polyhedrocytes) (Ci-iii) per image area in the outer layer, intermediate part, and center in blood clots with an increasing extent of contraction. Each dot represents a number calculated from 1 of 3 scanning electron micrograph (36 700 µm²) of a blood clot from 9 independent blood samples. Results are presented as the median with interquartile range. Statistical analysis: Friedman test with post hoc Benjamini, Krieger, and Yekutieli test.