RP-HPLC analysis of radiolabeled products biosynthesized by the native PfFPPS in 5 × 1010semipurified Plasmodium falciparum schizont stages. Extracts of parasites were obtained with methodology described by Tonhosolo et al. . The reaction of [4-14C]IPP with three allylic substrates: DMAPP, GPP, or FPP were realized. Arrows indicate the elution positions of isoprenoid standards. The retention times of GPP, FPP and GGPP were identified by co-injection of commercial standards. (A) DMPP substrate, (B) GPP substrate, and (C) FPP substrate.