$fracture 2007$

$fracture 2007$

Demonstration of the outer surface of freeze-etched red blood cell membranes. Membrane structure as seen with a double replica method for freeze-fracturing. Covalently bound ferritin as a membrane marker. A simple freeze-fracture replication method for electron microscopy.

$fracture 2007$

Fine structure of frozen-etched yeast cells. Electron microscopy of structural detail in frozen biological specimens. Images provided by freeze fracture and related techniques have profoundly shaped our understanding of the functional morphology of the cell. Deep etching of ultrarapidly frozen samples permits visualization of the surface structure of cells and their components. Freeze fracture is unique among electron microscopic techniques in providing planar views of the internal organization of membranes. An optional etching step, involving vacuum sublimation of ice, may be carried out after fracturing. In routine protocols, a pretreatment step is carried out before freezing, typically comprising fixation in glutaraldehyde followed by cryoprotection with glycerol. The four key steps in making a freeze-fracture replica are (i) rapid freezing, (ii) fracturing, (iii) replication and (iv) replica cleaning. The freeze-fracture technique consists of physically breaking apart (fracturing) a frozen biological sample structural detail exposed by the fracture plane is then visualized by vacuum-deposition of platinum–carbon to make a replica for examination in the transmission electron microscope.

$fracture 2007$

Fracture 2007