Plasmolysis

Plasmolysis
A red blood cell in a hypertonic solution, causing water to move out of the cell.
Specialty	Cell biology
Causes	Osmosis

Before plasmolysis (top) and after (bottom)

Plasmolysis is the process in which cells lose water in a hypertonic solution. The reverse process, deplasmolysis or cytolysis, can occur if the cell is in a hypotonic solution resulting in a lower external osmotic pressure and a net flow of water into the cell. Through observation of plasmolysis and deplasmolysis, it is possible to determine the tonicity of the cell's environment as well as the rate solute molecules cross the cellular membrane.