Acoustophoretic synchronization of mammalian cells in microchannels.

We report the first use of ultrasonic standing waves to achieve cell cycle phase synchronization in mammalian cells in a high-throughput and reagent-free manner. The acoustophoretic cell synchronization (ACS) device utilizes volume-dependent acoustic radiation force within a microchannel to selectively purify target cells of desired phase from an asynchronous mixture based on cell cycle-dependent fluctuations in size. We show that ultrasonic separation allows for gentle, scalable, and label-free synchronization with high G(1) phase synchrony (approximately 84%) and throughput (3 x 10(6) cells/h per microchannel).