Expression analysis of MSP3-like ORFs. IFA analysis of acetone-fixed thin smear of the blood stage parasites, using the same antibodies used for Western blot analysis, shows merozoite surface staining. The size-bar drawn in the lower right-hand corner of each microscopic field represents 5 mm. Antibodies affinity-purified against the unique region of MSP3.5 did not react to parasite proteins in IFA.Singh S, Soe S, Weisman S, Barnwell JW, Pérignon JL, Druilhe P. A conserved multi-gene family induces cross-reactive antibodies effective in defense against Plasmodium falciparum. PLoS One. 2009;4(4):e5410.

Immunofluorescence detection of MSP-636 in acetone-fixed P. falciparum T9:96 schizonts. Panels A to C show the reaction with antibodies raised to a recombinant fusion protein containing the last 45 amino acids of MSP-6; panels D, E, and F show the reaction of MSP-1 specific mAbs X509, 1E1 and 8A12, respectively. MSP-636 is the processed product of the precursor merozoite surface protein 6 (MSP-6). Results show that antibodies bound to antigen at the parasite surface or in the parasitophorous vacuole within schizonts, with a pattern indistinguishable from that of antibodies to MSP-1.Trucco C, Fernandez-Reyes D, Howell S, Stafford WH, Scott-Finnigan TJ, Grainger M, Ogun SA, Taylor WR, Holder AA. The merozoite surface protein 6 gene codes for a 36 kDa protein associated with the Plasmodium falciparum merozoite surface protein-1 complex. Mol Biochem Parasitol. 2001 112:91-101. . Copyright Elsevier 2010.

Processed Peripheral MSPs become part of an anchored complex late in schizogony. Immunofluorescence assays of Trophozoites (28-32 hr) in columns 1 (Phase + 488 + DAPI) and 2 (488 + DAPI), Schizonts (44-48 hr) in columns 3 (Phase + 488 + DAPI) and 4 (488 + DAPI) and PEMS (E64 treated) in columns 5 (Phase + 488 + DAPI) and 6 (488 + DAPI) were probed with monoclonal antibodies (green); 9A6 (anti-MSP1 p83), 9A12 (anti-MSP3), 2C12 (anti-MSP6), 7H12 (anti-MSPDBL1), 4A7 (anti-MSPDBL2) and 8F1 (anti-MSP7). EXP2 was used as an expression control probed with polyclonal rabbit anti-EXP2 antibodies (red). The nuclei of parasites are stained with DAPI (blue).Lin CS, Uboldi AD, Epp C, Bujard H, Tsuboi T, Czabotar PE, Cowman AF. Multiple P. falciparum Merozoite Surface Protein 1 Complexes Mediate Merozoite Binding to Human Erythrocytes. J Biol Chem. 2016 Jan 28. [Epub ahead of print] PMID: