Evolution of cell deformability during the maturation of P vivax. (A) Representative micropipette aspiration images of CD71⁺ and CD71⁻ reticulocytes and of P vivax IRBCs at the different maturation stages (based on the size of the parasitophorous vacuole and arrangement of hemozoin). (B) Key examples of single-cell measurements of cell length aspirated with different pressure intensities. Also provided is a diagram (upper left corner) and the equation (lower left corner) to show how the shear flow modulus for each cell was calculated. ΔL, aspirated length; ΔP, aspirating pressure; D, micropipette inner diameter; dL/dP, slope of the linear region of the aspiration graph as shown in this figure. (C) The median shear flow modulus (± interquartile range) of each population. Note that the uninfected CD71⁺ reticulocytes and tiny ring forms have the highest shear modulus (ie, the most rigid cells), which was significantly higher than any of the other normocytes and other infected red cells. n.s., not significant.