Using sound waves, researchers from the National Institute of Biomedical Imaging and Bioengineering gently culled circulating tumor cells (CTCs) from blood samples. The contact-free nature of the method assures that original cell characteristics are maintained.

The low-cost acoustic cell-separation device was developed by a research team led by Tony Jun Huang, Ph.D., at Pennsylvania State University, and his collaborators at the Massachusetts Institute of Technology, Notre Dame University, Penn State Hershey Cancer Center, and Carnegie Mellon University. The gentle and efficient acoustic tweezers can move and manipulate thousands of cells.

The new method uses sound, or acoustic waves, similar to the waves in an ultrasound imaging test, to separate CTCs from other blood cells. Cancer patients' blood samples are streamed across a microfluidic chip where only a fraction of a second of acoustic waves can separate the blood cells from the CTCs, based on their significant difference in size and weight. The brief acoustic exposure exerts little to no stress on the cells.

Improved efficiency of the acoustic separation of CTCs is expected to enhance performance in other applications as well, such as separating blood components, synchronizing cells for precise studies of cell division and growth, and separating bacteria from blood and other body fluids.