Immunolocalization of β-giardin in WB and GS trophozoites. Reactivity of 12G5 mAb on WB and GS Giardia trophozoites was determined by indirect immunofluorescence in permeabilized trophozoites. (A) Upper panel: immunofluorescence assays showing the labelling in the ventral disc of the trophozoites. Lower panels: high magnification showing the immunostaining in the ventral disc of WB trophozoites, with more intensity on the margins. (B) Upper panel: immunofluorescence of β-giardin in GS trophozoites. Lower panels: high magnification showing immunofluorescence specifically organized into a radial array surrounding the half ring of the ventral disc and also at the centre of it. Scale bar: 10 μm.