Extended Data Fig. 7: Ultrasound images comparing GV expression in bacteria and mammalian cells.
From: Acoustically triggered mechanotherapy using genetically encoded gas vesicles
(a) Ultrasound images of agarose phantoms containing S. typhimurium cells expressing GVs . The initial frame shows the echo from collapsing GVs (left, Peak US,), and the second one presents the residual signal from the cells after bubble dissolution (middle, Collapsed). The GV-specific signal, calculated as the difference between these two images, reveals high GV content in bacteria (right, Difference). (b) Ultrasound images of agarose phantoms containing GV-expressing HEK293 cells. The bacteria and mammalian cell samples were loaded into agarose phantoms at the same concentration as used in cavitation experiments. The volume of each well was 25 µl and it contained either 2 × 105 trypsinized mARG-HEK cells or OD600 = 1 (about 2 × 106) GV-expressing S. typhimurium cells. The combined volume of the mARG-HEK cells greatly exceeds the combined volume of the bacterial cells. However, the partial volume occupied by GVs in mammalian cell is much lower than in bacteria, resulting in lower GV-specific signal.
