In situ observation of freeze-fractured and deep-etched red blood cells with a high-vacuum low-temperature atomic force microscope

A high-vacuum low-temperature atomic force microscope (AFM) for the direct observation of freeze-fracture samples has been developed. This AFM has a freeze-fracture mechanism inside the vacuum chamber. With this AFM it is possible to observe the fractured surface directly without both fabricating a replica and exposure to the ambient atmosphere. Both sandwich and knife fracture methods have been achieved to obtain freeze-fracture surfaces and after deep etching. A fine structure of the fractured red blood cell membrane has been observed using both methods. These are relatively quick and easy methods for the observation of freeze-fracture surfaces without introducing replica artifacts.