A method and apparatus for measuring changes in cell volume generally includes introducing cells into a chamber having a volume between 2 and 100 times the volume of the introduced cell. A first electrically conductive extracellular fluid is introduced into the chamber and a current is applied. The voltage induced by said current flow is measured. The first fluid is exchanged with a second electrically conductive extracellular fluid and a current is applied. The voltage induced by said current flow is measured. The first induced voltage result and the second induced voltage result are used in conjunction with known voltages induced by such current flows to monitor changes in the volume corresponding to fluid flow between the cell and an extracellular fluid.