Ultrasound imaging of gene expression in mammalian cells

Abstract

Sounding out mammalian cells Live cell imaging allows us to observe cellular processes in real time. Most methods rely on light, and the poor penetration of light into tissues limits their application. Ultrasound penetrates tissues, and cellular reporters that respond to ultrasound have been developed recently. These reporters are air-filled protein structures that provide buoyancy in the bacteria they are derived from, but when surrounded by a fluid medium, they reflect sound waves. Farhadi et al. achieved expression from multiple genes to create these complex structures in mammalian cells. In addition to optimizing reporter production and detection, they visualize cells in a proof-of-principle experiment in mouse tumor xenografts. Science , this issue p. 1469