Freeze dryers: principle of lyophilization

LyophilisateurLyophilization, or cold drying, is a process which removes the water contained in a sample in order to make it stable at room temperature and facilitate its conservation. Lyophilization uses a very simple physical principle called sublimation. Sublimation is the passage of an element from the solid state to the gaseous state directly without passing through the liquid state. In the case of water to be removed from the samples, the lyophilization steps are:

- Freezing the samples at -20 ° C so that the water they contain is in the form of ice.
- Then under the effect of vacuum, sublimation of the ice directly into water vapor.
- Condensation of water vapor using a trap or condenser (temperature  -50 ° C / -60 ° C).
- Once all the ice has sublimated, cold drying the samples.

Centrifugal vacuum evaporator

speedvac 150x200The centrifugal concentrator is intended for sample preparation. The centrifugal force prevents the spraying of solutions allowing to concentrate and recover the maximum of molecules during extraction. The vacuum and the possibility of heating accelerate the evaporation of solvents.