Visualization of freezing damage.
Visualization of freezing damage.
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DOI：
10.1083/jcb.57.3.729
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发表时间：
1973-06
期刊：
影响因子：
--
通讯作者：
Mazur P
中科院分区：
文献类型：
--
作者：
Bank H;Mazur P
冷冻裂解可用作直接探针来检查生物材料因冷冻而发生的超微结构变化。我们研究了这样的论点：至少有两个与冷却速度相反的因素决定了冷冻细胞的存活率。根据该论文，当细胞以超过临界速度的速度冷却时，细胞内冰的存在会导致活力下降；但以低于该临界速度的速率冷却的细胞不含有明显量的细胞内冰，并且由于长时间暴露于因冰的存在而改变的溶液而被杀死。作为对这一假设的检验，我们在悬浮液以 1.8 至 75,000°C/min 的速率冷却后检查了酿酒酵母的冷冻断裂复制品。一些冷冻样品被立即切割和复制，以尽量减少样品处理造成的伪影。其他样品经过深度蚀刻或在复制前重新加热至 -20°C 并重新冷却。酵母细胞冷却至或高于保持最大活力所需的速率（~7°C/分钟）含有细胞内冰，而冷却至低于该速率的细胞则没有细胞内冰的证据。
Freeze-cleaving can be used as a direct probe to examine the ultrastructural alterations of biological material due to freezing. We examined the thesis that at least two factors, which are oppositely dependent upon cooling velocity, determine the survival of cells subjected to freezing. According to this thesis, when cells are cooled at rates exceeding a critical velocity, a decrease in viability is caused by the presence of intracellular ice; but cells cooled at rates less than this critical velocity do not contain appreciable amounts of intracellular ice and are killed by prolonged exposure to a solution that is altered by the presence of ice. As a test of this hypothesis, we examined freeze-fractured replicas of the yeast Saccharomyces cerevisiae after suspensions had been cooled at rates ranging from 1.8 to 75,000°C/min. Some of the frozen samples were cleaved and replicated immediately in order to minimize artifacts due to sample handling. Other samples were deeply etched or were rewarmed to -20°C and recooled before replication. Yeast cells cooled at or above the rate necessary to preserve maximal viability (∼7°C/min) contained intracellular ice, whereas cells cooled below this rate showed no evidence of intracellular ice.