SELECTIVE RETENTION OF VIABLE CELLS IN ULTRASONIC RESONANCE FIELD DEVICES

A double-chamber ultrasonic resonance field device was used for the se paration and retention of animal cells. By controlling operational par ameters such as flow and power input, the device can retain viable cel ls more efficiently, allowing for selective removal of nonviable cells and cell debris. A simple model describing the forces acting on spher ical particles in a sound field (primary radiation force, Bernoulli fo rce, secondary radiation force) is presented. Field stability increase s with decreasing average flow rates and increasing power input. At ve ry high field stability, as achieved with low flow rates and high powe r input, the selectivity for viable cells is reduced, due to the effic ient retention of all types of particles. At high flow rates and resul ting low field stability, selectivity is also reduced, due to poor sep aration efficiency, resulting in equally low retention of viable cells , nonviable cells, and cell debris.