Expansion Microscopy of trichomonads

Light microscopy has significantly advanced in recent decades, especially concerning the increased resolution obtained in fluorescence images. Here we present the Expansion Microscopy (ExM) technique in two parasites, Trichomonas vaginalis and Tritrichomonas foetus, which significantly improved the localization of distinct proteins closely associated with cytoskeleton by immunofluorescence microscopy. The ExM techniques have been used in various cell types, tissues and other protist parasites. It requires the embedment of the samples in a swellable gel that is highly hydrophilic. As a result, cells are expanded 4.5 times in an isotropic manner, offering a spatial resolution of -70 nm. We used this new methodology not only to observe the structural organization of protozoa in more detail but also to increase the resolution by immunofluorescence microscopy of two major proteins such as tubulin, found in structures formed by microtubules, and costain 1, the only protein identified until now in the T. foetus's costa, a unique rod-shaped like structure. The individualized microtubules of the axostyle were seen for the first time in fluorescence microscopy and several other details are presented after this technique.

Automated summary

Light microscopy has made significant advancements in fluorescence image resolution, particularly with the use of the Expansion Microscopy (ExM) technique. This article presents the application of ExM in two parasites, Trichomonas vaginalis and Tritrichomonas foetus, demonstrating improved localization of cytoskeleton-associated proteins through immunofluorescence microscopy. The ExM technique expands cells isotropically by embedding samples in a highly hydrophilic gel, resulting in a 4.5-fold expansion and a spatial resolution of approximately 70 nm. This new methodology allows for detailed observation of protozoa structural organization and enhanced resolution in the imaging of major proteins.