Great paper from Mikhail Shapiro’s lab where Nyström et al. used directed evolution methods to create protein gas vesicles which respond to distinct acoustic pressures, allowing for ultrasound imaging in two ‘colors’! Of note, Mikhail Shapiro is involved in the extremely exciting Merge Labs, which was publicly announced recently. [ https://www.nature.com/articles/s41592-025-02825-w](https://www.nature.com/articles/s41592-025-02825-w)

Ultrasound imaging with acoustic reporter genes has been limited to a single ‘tone’, restricting the types of experiments that can be achieved. This work introduces two acoustic reporter genes that enable multiplexed imaging in vitro and in mice.