ELECTRON-MICROSCOPY OF FROZEN BIOLOGICAL SUSPENSIONS
ELECTRON-MICROSCOPY OF FROZEN BIOLOGICAL SUSPENSIONS
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DOI：
10.1111/j.1365-2818.1983.tb04163.x
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发表时间：
1983-01-01
影响因子：
2
通讯作者：
DUBOCHET, J
中科院分区：
文献类型：
--
作者：
LEPAULT, J;BOOY, FP;DUBOCHET, J
使用晶体和T4噬菌体评估冷冻水合状态下制备标本的方法。这些方法也用.lambda进行了演示。噬菌体，嗜盐细菌的紫色膜和DNA纤维。对于分散在水环境中的颗粒，在玻璃体状态的大块水介质中，通过薄的淬火冷冻膜可以获得最佳的结构保存。大块水的结晶可能导致溶质偏析和试样从薄膜中排出。对比测量可用于直接跟踪试样从完全水化到冻干状态的水化状态，并允许直接测量试样的含水量。通过改变水介质的浓度和组成，可以控制玻璃体膜中颗粒的对比度，并可以获得负、正或零对比度的任何状态。为100.度。在室温下，与类似的糖包埋或冷冻干燥样品相比，K，冷冻水合，冷冻干燥或糖包埋的晶体在相同的损伤下可以承受3到4倍的电子暴露。
The methodology for preparing specimens in the frozen hydrated state was assessed using crystals and T4 bacteriophages. The methods have also been demonstrated with .lambda. bacteriophages, purple membrane of Halobacterium halobium and fibers of DNA. For particles dispersed in an aqueous environment, optimum structural preservation is obtained from a thin, quench-frozen film with the bulk aqueous medium in the vitreous state. Crystallization of the bulk water may result in solute segregation and expulsion of the specimen from the film. Contrast measurements can be used to follow directly the state of hydration of a specimen during transition from the fully hydrated to the freeze-dried state and permit direct measurement of the water content of the specimen. By changing the concentration and composition of the aqueous medium, the contrast of particles in a vitreous film can be controlled and any state of negative, positive or zero contrast may be obtained. At 100.degree. K, frozen-hydrated, freeze-dried or sugar embedded crystals can withstand a 3- to 4-fold increase in electron exposure for the same damage when compared with similar sugar-embedded or freeze-dried samples at room temperature.