Which of the following is the preparation method particularly useful for examining lipid membranes and their incorporated proteins in Electron Microscopy?

Freeze-fracture or freeze-etch – a preparation method particularly useful for examining lipid membranes and their incorporated proteins in face on view. The fresh tissue or cell suspension is frozen rapidly (cryofixation), then fractured by simply breaking or by using a microtome while maintained at liquid nitrogen temperature. The cold fractured surface (sometimes etched by increasing the temperature to about −100 °C for several minutes to let some ice sublime) is then shadowed with evaporated platinum, or gold at an average angle of 45° in a high vacuum evaporator