Freeze Etching

**Definition:** A replica technique in which cells are frozen to a very low temperature and cracked with a knife blade to expose the interior surfaces of the cells or cell membranes. The cracked cell surfaces are then freeze-dried to expose their constituents. The surfaces are now ready for shadowing to be viewed using an electron microscope. This method differs from freeze-fracturing in that no cryoprotectant is used and, thus, allows for the sublimation of water during the freeze-drying process to etch the surfaces.

**Tree numbers:** - E01.370.225.500.620.620.260.400 - E01.370.225.750.600.620.260.400 - E05.200.500.620.620.260.400 - E05.200.750.600.620.260.400