3D manipulation of small multicellular organisms in soft microtubes

Small multicellular organisms, such as C. elegans and zebrafish larvae, are essential models in biological research, but their 3D manipulation poses challenges due to their small size. Manual positioning is labor-intensive and imprecise. To address this, we developed a soft PDMS microtube that can be gently stretched and released, immobilizing organisms without anesthetization and damage. This tube enables easy rotation and adjustment of orientation, facilitating comprehensive imaging. Functionality testing showed effective immobilization as well as precise imaging and microinjection. Zebrafish larvae were successfully injected with fluorescein in the hindbrain without anesthesia. This technique offers a simple, efficient, and non-damaging method for 3D manipulation and imaging of small multicellular organisms and provides a versatile tool for biological research practices.