standard freezing specimen stage with sample liquid propane - 196 °C liquid nitrogen - 196 °C jet freezing

cryofixation Cryofixation is a physical fixation method: an ultra-rapid immersion of the sample into the cryogen (propane or freon on the temperature of liquid nitrogen). Successful ultra-rapid freezing requires heat be withdrawn so rapidly from an unfixed, un-cryoprotected sample so that the ultrastructure is preserved and no ice crystal damage is visible at the electron microscopic level of analysis . standard freezing The specimen support holding the sample is plunged into liquid propane or other suitable croygens as fast as possible. The achievable rate of cooling with this method is about 1000 K/s. jet freezing Liquid propane is driven from opposite directions onto a specimen sandwich which consists of two specially designed copper or gold platelets. This technique provides higher rates of cooling up to 10.000 K/s.