The Leica EM GP2 Plunge Freezer is a cryo-fixation method used to preserve samples in their most native state prior to cryo-electron microscopy. The EM GP2 plunge freezes fluid or extremely thin samples spread on an electron microscopy grid into liquid ethane after removing excess fluid by automatic blotting. Prior to freezing, the sample is maintained in a temperature and humidity controlled environmental chamber, adjustable between +4°C and +60°C and room humidity to 99 %.