Credit: Junjie Yao and Lihong Wang
Deep-tissue in vivo photoacoustic genetic imaging of reversibly switchable bacterial phytochrome BphP1. The reversible switching of BphP1 enables differential photoacoustic imaging, which dramatically enhances the detection sensitivity of a BphP1-expressing tumor (shown in color scale) in the mouse brain. The overwhelming background signals from non-switchable blood vessels are shown in gray scale.