Obviously, some samples can stand air drying better than others. Others such as animal tissue culture, and protists become virtually unrecognizable. Avoid liquid - gas interface, particularly that between water and air. This method eliminates the liquid-gas interface by tying up specimen water as ice by changing it from the solid to the gaseous state. Equipment - a simple vacuum chamber.
Some dedicated models have a cooling and heating stage.
This ties up all of the tissue water as ice. Sample is then placed into a vacuum chamber and temperature maintained by a cold stage. Advantages - unfixed fresh tissue can be used. Organic solvents are avoided - these are used in some other techniques. Disadvantages - causes severe shrinkage in many specimens, ie skin and muscle.