A Non-Invasive, Label-Free Method for Examining Tardigrade Anatomy Using Holotomography.

BACKGROUND/OBJECTIVES: Holotomography is an advanced imaging technique that enables high-resolution, three-dimensional visualization of microscopic specimens without the need for fixation or staining. Here we aim to apply holotomography technology to image live in their native state, avoiding invasive sample preparation procedures and phototoxic effects associated with other imaging modalities.

METHODS

We use a low concentration of 7% ethanol for tardigrade sedation and sample preparation. Holotomographic images were obtained and reconstructed using the Tomocube HT-X1 system, enabling high-resolution visualization of tardigrade anatomical structures.

RESULTS

We captured detailed, label-free holotomography images of both external and internal structures of tardigrade, including the digestive tract, brain, ovary, claws, salivary glands, and musculature.

CONCLUSIONS

Our findings highlight holotomography as a complementary high-resolution imaging modality that effectively addresses the challenges faced with traditional imaging techniques in tardigrade research.