On-Demand Droplet Loading of Ultrasonic Acoustic Levitator with Small Droplets for Protein Crystallography Application

Ultrasonic acoustic levitation has been recently applied successfully for protein crystallography experiments. One of the development goals of such an acoustic levitation diffractometer is to realize a fully automated high-throughput crystallography pipeline at room temperature that integrates an on-demand sample delivery mechanism from crystallization plates. To study the feasibility of the on-demand droplet ejection from crystallization plates, we prepared acoustic ejectors and tested their characteristics. Acoustic droplet ejection from a vertically positioned crystallization plate and coalescence of the ejected droplet with the levitated droplet in an acoustic levitator was successfully demonstrated, indicating that feasibility of the proposed instrument.