Plunge Freezing for Cryo-EM

To conserve protein samples in their most natural state for the investigation by TEM these samples are usually vitrified using liquid ethane. This process allows exposure to the electron beam under high vacuum without the sample drying out and is referred to as Cryo-EM.

The goal of this preparation process is to create an electron transparent film of amorphous/vitrified ice containing the protein sample, suspended across holes of typically 2–3 µm diameter within a 3 mm TEM specimen grid. For this purpose, a (semi-)automatic vitrification devices like the ThermoFisher Scientific Vitrobot Mark IV  or the Gatan Cryoplunge™ 3 with GentleBlot™ can be used.