In Vitro picosecond ultrasonics in a single cell

Ultrasonics signals at frequencies 5.7±0.1 and 6.8±0.1GHz 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±0.1μm∕ns are measured from several signals recorded in the vacuole and in the nucleus of a single Allium cepa cell, respectively. A 1μm lateral and 0.25μm depth resolution is attained.