New synchronization method for Plasmodium falciparum.
BACKGROUND
Plasmodium falciparum is usually asynchronous during in vitro culture. Although various synchronization methods are available, they are not able to narrow the range of ages of parasites. A newly developed method is described that allows synchronization of parasites to produce cultures with an age range as low as 30 minutes.


METHODS
Trophozoites and schizonts are enriched using Plasmion. The enriched late stage parasites are immobilized as a monolayer onto plastic Petri dishes using concanavalin A. Uninfected erythrocytes are placed onto the monolayer for a limited time period, during which time schizonts on the monolayer rupture and the released merozoites invade the fresh erythrocytes. The overlay is then taken off into a culture flask, resulting in a highly synchronized population of parasites.


RESULTS
Plasmion treatment results in a 10- to 13-fold enrichment of late stage parasites. The monolayer method results in highly synchronized cultures of parasites where invasion has occurred within a very limited time window, which can be as low as 30 minutes. The method is simple, requiring no specialized equipment and relatively cheap reagents.


CONCLUSIONS
The new method for parasite synchronization results in highly synchronized populations of parasites, which will be useful for studies of the parasite asexual cell cycle.
Ranford-Cartwright
Lisa C
LC
Division of Infection and Immunity, Faculty of Biomedical and Life Sciences, University of Glasgow, Glasgow Biomedical Research Centre, Glasgow G12 8TA, Scotland. L.ranford-cartwright@bio.gla.ac.uk
Sinha
Abhinav
A
Humphreys
Georgina S
GS
Mwangi
Jonathan M
JM
D000818:Animals; D002478:Cells, Cultured; D003208:Concanavalin A; D003470:Culture Media; D046508:Culture Techniques / Q000379:methods*; D004912:Erythrocytes / Q000469:parasitology*; D005780:Gelatin; D008934:Mitogens; D010952:Plasma Substitutes; D010963:Plasmodium falciparum / Q000254:growth & development* / Q000302:isolation & purification; D052939:Schizonts / Q000469:parasitology; D053058:Trophozoites / Q000469:parasitology
D003470:Culture Media; D008934:Mitogens; D010952:Plasma Substitutes; D003208:Concanavalin A; C013648:plasmion; D005780:Gelatin