Provided is a method of transporting fluid which involves acoustic
ejection into a small opening. The opening may be, for example, the inlet
opening of a sample vessel. Alternatively, it may be an opening in a
microfluidic device. The ejection is typically, but not necessarily
carried out through the application of focused acoustic energy. The fluid
being transported typically comprises a moiety of interest for analysis
or further processing, which may be a biomolecule. The volumes of
transported fluid may be in the nanoliter or picoliter range. Ejection
may occur from very small volumes and the ejected droplet may carry away
a significant fraction of the volume from which ejection occurs.