Simultaneous recording of the surface and internal structures of helminth parasites by fluorescence stereomicroscopy and light-sheet fluorescence microscopy (LSFM)

The study of helminth parasites has been carried out using different microscopy tools such as bright-field, fluorescence, confocal, and electron microcopies, providing morphological and ultrastructural information, which are important for morphological taxonomy. However, these microscopy techniques are unable to visualize both surface and internal structures simultaneously at high resolution in a single analysis. Consequently, researchers must use different tools to enhance the knowledge of helminths and other parasites. The present work highlights the importance of using a fluorescence stereomicroscopy based in the structured illumination to visualize simultaneously the surface and internal structures of helminth and other metazoan samples. Our results using a single equipment showed the surface topography and internal structures of the whole parasite simultaneously. In addition, the series of images can be applied to produce a three-dimensional (3D) model of the samples. These advanced methods can indeed open new frontiers for obtaining better morphological data, enriching the knowledge in helminthology, and enhancing studies of other invertebrates, especially where thick samples, which are common, are present. Recent studies with large and thick helminths have provided 2D and 3D visualization of the whole parasite. This represents an important advance in the investigation of helminth parasitology, invertebrate morphophysiology, and other areas of microanatomy study in metazoans.