the pressure probe , which is routinely used to measure the turgor potential ( psi ( p ) ) of individual epidermal cells in tradescantia virginiana ( l. ) , has also been used to sample small volumes of vacuolar fluid from these same cells ( as low as 0.02 nl ) for measurement of cellular solute ( osmotic ) potential ( psi ( s ) ) in a micro freezing point osmometer .
C0042219
vacuolar
C0007634
cells