Table 1.

CQ IC₅₀ values for the pfcrt transfectant lines and the (nontransfectant) 3D7 and 7G8 strains, as determined using 48-h and 72-h [³H]hypoxanthine incorporation assays^a

Parasite line	Mean CQ IC50 ± SEM (nM)		P value (no. of experiments)b
	48 h	72 h
D10C	9.1 ± 0.7	7.2 ± 0.6	0.07 (6)
D107G8	24.9 ± 0.7	10.2 ± 0.8	<0.001 (5)
3D7C	5.3 ± 0.4	4.3 ± 0.2	0.05 (3)
3D77G8	35.7 ± 1.8	14.2 ± 2.0	<0.001 (5)
GC03C	7.2 ± 0.6	7.0 ± 0.6	0.9 (4)
GC037G8	39.4 ± 1.6	33.6 ± 2.0	0.05 (6)
3D7	4.8 ± 0.2	4.6 ± 0.2	0.6 (6)
7G8	95 ± 4	48 ± 5	0.002 (3)

^aThe pfcrt transfectant lines were made by Valderramos et al. (40). In each assay, [³H]hypoxanthine was added 24 h before the termination of the assay. The IC₅₀s are averaged from those obtained in 3 to 6 separate experiments. The 48-h and 72-h assays were set up concurrently.

^bP values as determined for 48-h versus 72-h IC₅₀s, unpaired t tests.