A. Purified trophozoite-stage iRBCs and matched uRBCs were labeled with one of ten 13C-substrates (listed in purple). All mass-to-charge (m/z) features identified by LC-MS were extracted and isotopologues grouped. 13C-labelled and 12C-labelled isotopologue groups were compared to identify m/z features in each cell type and that were differentially labelled between iRBC and uRBC. Putative metabolite identities were then confirmed with authentic standards, MS/MS spectral matching, 13C-labelling profile, and exact mass. The observed metabolic network of each cell type was then constructed using the draft metabolome and 13C-labelling information and compared to the predicted P. falciparum metabolome reported by Huthmacher et al. (2010). 