title: Identification and classification of the malaria parasite blood developmental stages, using imaging flow cytometry.
abstract: Malaria is the most devastating parasitic disease of humans, caused by the unicellular protozoa of the Plasmodium genus, such as Plasmodium falciparum (Pf) and is responsible for up to a million deaths each year. Pf life cycle is complex, with transmission of the parasite between humans via mosquitos involving a remarkable series of morphological transformations. In the bloodstream, the parasites undergo asexual multiplications inside the red blood cell (RBC), where they mature through the ring (R), trophozoite (T) and schizont (S) stages, and sexual development, resulting in gametocytes (G). All symptoms of malaria pathology are caused by the asexual blood stage parasites. Flow cytometry methods were previously used to detect malaria infected (i) RBCs, in live or fixed cells, using DNA (Hoechst) and RNA (Thiazole Orange) stains. Here, by using imaging flow cytometry, we developed improved methods of identifying and quantifying each of the four parasite blood stages (R, T, S and G). This technique allows multi-channel, high resolution imaging of individual parasites, as well as detailed morphological quantification of Pf-iRBCs cultures. Moreover, by measuring iRBC morphological properties, we can eliminate corrupted and extracellular (dying) parasites from the analysis, providing accurate quantification and robust measurement of the parasitemia profile. This new method is a valuable tool in malaria molecular biology research and drug screen assays.
authors.affiliation: Faculty of Biochemistry, Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel.
authors.forename: Elya
authors.initials: E
authors.lastname: Dekel
authors.affiliation: Faculty of Biochemistry, Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel.
authors.forename: Anna
authors.initials: A
authors.lastname: Rivkin
authors.affiliation: Faculty of Biochemistry, Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel.
authors.forename: Meta
authors.initials: M
authors.lastname: Heidenreich
authors.affiliation: Faculty of Biochemistry, Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel.
authors.forename: Yotam
authors.initials: Y
authors.lastname: Nadav
authors.affiliation: Faculty of Biochemistry, Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel.
authors.forename: Yifat
authors.initials: Y
authors.lastname: Ofir-Birin
authors.affiliation: Flow Cytometry Unit, Biological Services Department, Weizmann Institute of Science, Rehovot, Israel. Electronic address: ziv.porat@weizmann.ac.il.
authors.forename: Ziv
authors.initials: Z
authors.lastname: Porat
authors.affiliation: Faculty of Biochemistry, Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel. Electronic address: neta.regev-rudzki@weizmann.ac.il.
authors.forename: Neta
authors.initials: N
authors.lastname: Regev-Rudzki
mesh_terms: D001399:Azure Stains / Q000737:chemistry; D001562:Benzimidazoles / Q000737:chemistry; D052160:Benzothiazoles / Q000737:chemistry; D002478:Cells, Cultured; D004912:Erythrocytes / Q000469:parasitology* / Q000648:ultrastructure; D005434:Flow Cytometry / Q000379:methods*; D005456:Fluorescent Dyes / Q000737:chemistry; D006801:Humans; D019044:Image Cytometry / Q000379:methods*; D008018:Life Cycle Stages / Q000502:physiology*; D010963:Plasmodium falciparum / Q000254:growth & development* / Q000648:ultrastructure; D011804:Quinolines / Q000737:chemistry; D013194:Staining and Labeling / Q000379:methods*
chemical_list: D001399:Azure Stains; D001562:Benzimidazoles; D052160:Benzothiazoles; D005456:Fluorescent Dyes; D011804:Quinolines; C051000:thiazole orange; C017807:bisbenzimide ethoxide trihydrochloride
keywords: Blood stage; Gametocytes; Imaging flow cytometry; Malaria; Plasmodium falciparum