Fig. 1.

Schematic for ex vivo experiments. Plasmodium vivax ex vivo experiments were divided into 2 phases. In Phase I, the schizont maturation test (SMT) was performed concurrently with the pLDH ELISA. Blood samples were processed to deplete white blood cells, and incubated with drugs of interest in parallel with whole blood samples. The SMT was conducted only in samples with ≥ 50% ring stages. *5 isolates with ring stage < 50% in initial samples were not tested for drug susceptibility, but 3 of them had Percoll treatment applied to separate late stage parasites and enrich for early stages for the SMT. In phase II, only pLDH ELISA was performed on whole blood samples. For P. falciparum testing, pLDH ELISA was performed concurrently with the HRP-2 ELISA with 48 h incubation times used in the pLDH ELISA to ensure meaningful comparison of P. vivax susceptibility, while the previously established 72 h incubation was followed for the HRP-2 method