Table 1.
Plasmion enrichment of trophozoites and schizonts in P. falciparum cultures
| Parasite | Parasitaemia before Plasmion (%) | Parasitaemia after Plasmion (%) | Enrichment factor | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Total | R | T | S | Total | R | T | S | Total | R | T | S | |
| 3D7 | 11.3 | 6.1 | 2.4 | 2.8 | 47.2 | 2.8 | 26.1 | 18.3 | 4.2 | 0.5 | 11.1 | 6.5 |
| 3D7 | 12.1 | 6.9 | 3.1 | 2.1 | 51.2 | 2.5 | 35.9 | 12.8 | 4.2 | 0.4 | 11.6 | 6.0 |
| HB3 | 9.8 | 4.8 | 2.6 | 2.4 | 62.6 | 2.1 | 26.3 | 34.2 | 6.4 | 0.4 | 10.1 | 14.3 |
| HB3 | 10.0 | 5.0 | 1.0 | 4.0 | 70.0 | 1.4 | 16.0 | 52.6 | 7.0 | 0.3 | 16.0 | 13.1 |
| XP5 | 13.0 | 6.0 | 3.0 | 4.0 | 66.8 | 2.8 | 29.0 | 35.0 | 5.1 | 0.5 | 9.7 | 8.8 |
| X12 | 10.2 | 4.0 | 1.1 | 5.1 | 78.1 | 2.1 | 22.0 | 53.9 | 7.7 | 0.5 | 22.0 | 10.8 |
| Mean enrichment | 5.78 | 0.4 | 13.4 | 9.9 | ||||||||
Asexual culture parasitaemia was estimated by examination of 2,000 erythrocytes for each culture, either immediately before or following enrichment with Plasmion. The numbers of ring (R), trophozoite (T) and schizont (S) stages present in each smear were also recorded. Trophozoites were distinguished from ring stage parasites by the appearance of pigment. Schizonts were distinguished from trophozoites by the presence of two or more nuclei. The enrichment factor was calculated by dividing the post-Plasmion treatment parasitaemia by that at pre-treatment.