Morphological Changes In Healthy And Malaria Infected Erythrocytes Probed By High Pressure Microscopy

A unique tool to investigate volume effects on the structure and metabolism of living cells is pressure perturbation. We present measurements of volume changes in healthy red blood cells (RBCs) and those infected with the malaria parasite Plasmodium falciparum over the pressure range from 0.1 to 210 MPa. The lateral diameter of healthy RBCs decreases reversibly with pressure with an approximate slope of 0.015 micron / MPa. In infected cells, we observe clear differences in the deformability and between the compression and decompression curves. The results are discussed with respect to the the spectrin molecular network and the cell membrane. Single cell absorption spectra of RBCs infected with the malaria parasite indicate hemoglobin degradation that can be correlated with the stages of the parasite multiplication cycle.