Schiller A, Taugner R
Cell Tissue Res. 1980;210(1):57-69. doi: 10.1007/BF00232141.
With the conventional freeze-fracture technique applied to biological specimens, cell membranes split along an interior plane and two membrane faces are produced. True membrane surfaces remain hidden and can only be uncovered by deep-etching. To date, deep-etching could not be satisfactorily performed in the presence of cryoprotective agents since conventional cryoprotectants do not sublime due to their low vapour pressure. This lack of suitable volatile cryoprotectants has limited deep-etching so far to very small objects which can be cryofixed without cryoprotectants. As a consequence, our freeze-fracture knowledge of cell surfaces is still poor. The present study shows that ethanol is a suitable volatile cryoprotectant for the freeze-fracture technique, and provides a novel approach to the routine deep-etching of freeze-fracture specimens without the need for special equipment. With ethanol deep-etching, true outer cell-surfaces are demonstrated within the kidneys of rat and Psammomys.
将传统的冷冻断裂技术应用于生物标本时，细胞膜会沿着内部平面分裂，从而产生两个膜面。真正的膜表面仍然隐藏着，只有通过深度蚀刻才能揭示出来。迄今为止，在存在冷冻保护剂的情况下，深度蚀刻无法令人满意地进行，因为传统的冷冻保护剂由于其低蒸气压而不会升华。缺乏合适的挥发性冷冻保护剂使得深度蚀刻目前仅限于非常小的物体，这些物体可以在没有冷冻保护剂的情况下进行冷冻固定。因此，我们对细胞表面的冷冻断裂知识仍然匮乏。本研究表明，乙醇是一种适用于冷冻断裂技术的挥发性冷冻保护剂，并提供了一种无需特殊设备即可对冷冻断裂标本进行常规深度蚀刻的新方法。通过乙醇深度蚀刻，在大鼠和沙鼠的肾脏中展示了真正的细胞外表面。
