Improved methods for the large-scale cultivation of Giardia lamblia trophozoites in the academic laboratory

The parasitic protist Giardia lamblia causes giardiasis, one of the leading diarrheal diseases worldwide. As a phylogenetically divergent eukaryote, Giardia is also an emerging model organism for exploring the diversity of core eukaryotic metabolic pathways and important molecular structures. To date, methods for the cultivation of large numbers (>109) of Giardia trophozoites have been either expensive or cumbersome, hampering structural and biochemical studies. Here, we present two improved strategies for the laboratory-scale growth of billions of adherent trophozoites, with suggestions for the optimization of media components, media preparation, and harvesting methods.