Using Sound Waves to Sort Cells
Just about every cancer can be a big problem, and all are dangerous when they spread, which makes it vitally important to know if it is. Catching cancer cells in a patient's blood is very difficult though, because of how few cells there can be, and that many methods for sorting cells are complicated or can damage the cells. Researchers at MIT, Pennsylvania State University and Carnegie Mellon University however, have developed a device for sorting cells with great accuracy, and relative ease.
Instead of relying on chemical tags or strong mechanical forces, this method utilizes sound waves to gently guide cells. By using two acoustic transducers on either side of a microchannel, a standing wave can be made with a pressure node parallel to the flow. This much has been accomplished before and did demonstrate that cells of different size, compressibility, and other properties, would be pushed around differently. What has been added now is a tilt, putting the pressure node at an angle, relative to the flow. This causes the cells to pass through multiple nodes, and be slightly pushed to one side, and cells of different physical properties are still affected differently.
The researchers have already tested it with plastic beads 9.9 and 7.3 microns in size, demonstrating 97% accuracy, and were able to recover 71% of cancer cells in a sample that included those and white blood cells. They also created a computer model that can predict how cells will be affected based on its properties and the angle of the sound waves, which opens up the possibility of device customization.