Non-Invasive Detachment of <i>Vorticella</i> from Calcium Alginate Membrane

Abstract

Non-invasive detachment of Vorticella from a substrate is essential for fabricating a microsystem based on Vorticella. Here, we dry sodium alginate solution and obtain sodium alginate films with fewer uncrosslinked sol regions. Calcium ions cross-link the alginate polymers of the membrane and form a calcium alginate gel. We first culture V. convallaria on the gel membrane. By dissolving the membrane with a chelating agent, we detatch cells non-invasively from the substrate and obtain cells with intact stalks, which can then be placed in a microsystem without waiting for the stalks to grow. The cells can be patterned by lift-off of the calcium alginate membrane. The proposed method provides new processing capabilities and allows for the design and fabrication of a system based on an actuator of Vorticella.

Reciprocation of micro-objects by contraction and extension of <i>Vorticella convallaria</i> using polylysine as adhesive material

“…To increase the torque, V. convallaria should be placed away from the axis of rotation. The position of V. convallaria can be controlled by trapping and closing V. convallaria in a microchamber with pneumatic valves (Nagai, et al, 2013b) or patterning a calcium alginate membrane (Nagai, et al, 2013a) and selectively dissolving the membrane. Whereas the V. convallaria cells displaced thin glass grits of thickness up to tens of micrometers, there was no noticeable displacement of grits thicker than 100 µm.…”