Figure 1.

Soft x-ray micrographs of intraerythrocytic ring stage P. falciparum malaria parasites imaged in normal erythrocytes. (A and B) Multiply infected erythrocytes from synchronized in vitro cultures were collected at the initiation of the experiment, washed three times in filtered PBS, and fixed in 1% or 2% glutaraldehyde. Ring stage parasites appeared discoidal and stippled. The darker area in the center of each parasite indicates more mass in the digestive vacuole (30 sec exposures). (C) An image of a singly infected erythrocyte removed from culture and fixed 6 hr after A and B shows a region of lower mass, compared with the erythrocyte cytosol, which extends from the parasite into the erythrocyte cytosol. This newly elaborated structure has not been seen before in fixed, unlabeled intact cells (exposure, 60 sec).