In Vitro picosecond ultrasonics in a single cell

Ultrasonics signals at frequencies 5.7 +/- 0.1 and 6.8 +/- 0.1 GHz are measured in two organelles of a single vegetal cell in vitro with a picosecond ultrasonic technique. Using standard values for cell optical index, ultrasound velocities of 1.6 +/- 0.1 and 2.0 +/- 0.1 mu m/ns are measured from several signals recorded in the vacuole and in the nucleus of a single Allium cepa cell, respectively. A 1 mu m lateral and 0.25 mu m depth resolution is attained. (C) 2008 American Institute of Physics.