Figure 3
Comparison of inhibitory concentration 50% (IC 50 ) calculated in vitro using 3 H-hypoxanthine, and TO/HE methods. Parasites were cultivated in standard microtest conditions. IC50 was calculated for chloroquine, using probit log transformation of the dose/effect curve. A/ Comparison of parasitaemia calculated using microscopy and TO/HE method. Ten field isolates were analysed. Parasitaemia are expressed as per cent of RBCs. Spearman correlation test between the two methods was 0.942. B/ Sensitivity (IC50 in nM) of Palo alto and 3D7 strains calculated for chloroquine using 3H-hypoxanthine and TO/HE methods. Seven independent experiments were done for each strains. C/ IC50 (in nM) of field isolates of Plasmodium falciparum for chloroquine, calculated using TO/HE or 3H hypoxanthine methods (21 isolates). D/ classification of the field isolates as sensitive/intermediate/resistant strains using the two methods.