Fig. 4.

Ciprofloxacin treatment of synchronized parasite populations. Parasites were synchronized with 5% sorbitol at 0, 48 h and 52 h. Rings were harvested at 55h, then treated for 30 min with solvent, 35 or 350 μM ciprofloxacin, lysed with SDS, digested with proteinase K and further processed for electrophoresis (lanes 3-5; 1.5 × 10⁷ parasitized erythrocytes/lane). Samples taken at 68 or 82 h for trophozoites (lanes 6-8; 1.4 × 10⁷ parasitized erythrocytes/lane) or schizonts (lanes 9-11; 7.1 × 10⁶ parasitized erythrocytes/lane), respectively, were then treated and processed as above. For lanes 4-11, total mass of plDNA relative to that in lane 3 was 0.93, 0.89, 1.1, 1.1, 1.1, 1.7, 1.5, 1.7, respectively, and percent linears in lanes 3-11 were 20, 27, 32, 20, 31, 33, 13, 34, and 47, respectively. Markers are EcoR I-linearized plDNA (lane 1) and UV-nicked plDNA (lane 2). N, nicked circular plDNA; L, linearized circles; CC, covalently closed circular plDNA. Arrow indicates well.