Launching Biological Samples with Sound

At first glance, this video might look like it's playing in reverse. But don't worry, these stroboscopic images were patched together in the right order.

The video shows a technique called acoustic drop ejection (ADE) - an idea based on sending ultrasonic waves near the surface of a liquid to eject very small droplets. First demonstrated in the early 1920s, ADE is now being used by researchers to help them study extremely small biological molecules - like proteins and viruses - with x-rays at machines like Brookhaven's future National Synchrotron Light Source II (NSLS-II).

NSLS-II's bright x-ray beams will enable scientists to reveal the atomic arrangement of increasingly smaller biological crystals - structures comprised of many copies of a particular molecule. But as a crystal's size decreases, it becomes harder for scientists to position it in the line of x-ray fire. To address this technological gap, scientists from Brookhaven and Labcyte, Inc. used ADE to launch very small droplets (2.5 nanoliters) containing even smaller biological crystals through the air and to a mounting mesh.

They found that the fragile microcrystals, which are nearly impossible to see even with powerful microscopes, were unharmed by the technique, paving the way for more studies of this kind. Their results were recently published in the journal, Biochemistry.

You can read more here.