Figure 2. Chemical reporters can be visualized in Toxoplasma tachyzoites via fluorescence microscopy.

(A) Parasites were incubated with Ac₄GlcNAz (0.5 mM) or Ac₄GlcNAc (0.5 mM) for 8 h, prior to fixation with 4% paraformaldehyde in PBS for 15 min at rt. Subsequent reaction with biotin-alk and incubation with streptavidin-AlexaFluor594 enabled fluorescence detection of modified bioconjugates. Exposure times were established with Ac₄GlcNAz samples and kept constant for the control samples. (B) Ac₄GlcNAz-treated parasites remain viable. Parasites were incubated with Ac₄GlcNAz (250 µM) or Ac₄GlcNAz (250 µM) for 8 h and then added to HFF monolayers. After 36 h, the samples were fixed, labeled, and imaged as in (A).