Evaluation of cryopreserved microtubules immobilized in microfluidic channels for a bead-assay-based transportation system

From an engineering point of view, a kinesin-microtubule biomolecular motor system is an attractive candidate as a driving force in the aqueous environment of micro total analysis systems (μTAS). We have studied fundamental components to be integrated in μTAS by implementing kinesin-microtubule systems into micro/nanoelectromechanical systems (MEMS/NEMS). This paper presents the cryopreservation technique of microtubules that are immobilized in a microfluidic device. Microtubules work as rail molecules along which kinesin-coated beads are transported; the functionality was preserved even after they were stored at -85°C for 30 days. This technique ensures that μTAS with immobilized microtubules can be prepared in advance and be thawed for use on demand.