title: Plasmodium falciparum: development and validation of a measure of intraerythrocytic growth using SYBR Green I in a flow cytometer.
abstract: Reliable analytical techniques to test growth-promoting and antimalarial efficacy on plasmodia are very important. Flow cytometry (FCM) offers the possibility to study developmental stages of intraerythrocytic growth of malaria parasites using nucleic acid staining. To analyze the growth of Plasmodium falciparum SYBR Green I was introduced as an intercalating dye with FCM for the 488nm line of an argon laser. Procedures employing FCM, including fixatives, dye concentrations, dilution buffer, and staining period, were optimized to simplify the method. FCM as described here allows parasitemia and parasites of different stages to be quantified according to the DNA content. The proportion of parasitized erythrocytes estimated by FCM and the Giemsa method agreed with determination by parasite lactate dehydrogenase. The protocol was extended to merozoite counting as a sensitive assay of growth inhibition of the parasite.
authors.affiliation: Department of Parasitology, National Institute of Infectious Diseases, Shinjuku-ku, Tokyo, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Izumiyama
authors.forename: Mako
authors.initials: M
authors.lastname: Omura
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Takasaki
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ohmae
authors.forename: Hiroko
authors.initials: H
authors.lastname: Asahi
mesh_terms: D000818:Animals; D052160:Benzothiazoles; D003959:Diamines; D004912:Erythrocytes / Q000469:parasitology*; D005434:Flow Cytometry / Q000295:instrumentation / Q000379:methods*; D005456:Fluorescent Dyes; D007770:L-Lactate Dehydrogenase / Q000032:analysis; D009930:Organic Chemicals; D010963:Plasmodium falciparum / Q000201:enzymology / Q000254:growth & development*; D011804:Quinolines; D012680:Sensitivity and Specificity
chemical_list: D052160:Benzothiazoles; D003959:Diamines; D005456:Fluorescent Dyes; D009930:Organic Chemicals; D011804:Quinolines; C098022:SYBR Green I; D007770:L-Lactate Dehydrogenase