CHARACTERIZATION OF FROZEN-HYDRATED SPECIMENS BY EELS

发展了一种测量亚细胞内水分含量的方法。 冰冻的水化组织的隔间，取决于 水与有机化合物的价态激发能量损失谱 细胞的组成成分。单次散射分布是第一 通过应用傅里叶对数从冰和蛋白质中获得 反褶积技术。然后将所得到的参考光谱 通过将Bethe和规则应用于差分振荡器来归一化 强度以求出不同的横截面。一位直接的 用最小二乘法可以得到含水率的估计值。 水合样品光谱的拟合算法。测试已经完成 快速冷冻牛血清白蛋白的薄层冷冻切片 标准，含有70%，80%和90%的蛋白质，通过记录 场发射扫描传输中的平行电致发光光谱 电子显微镜(STEM)。结果发现，精确度为 水含量的测定结果约为1%。 该方法已应用于冰冻红细胞和小脑。 大脑皮层。

A method has been developed for measuring water content in subcellular compartments of frozen hydrated tissue that depends on variations in the valence excitation energy loss spectrum between water and the organic constituents of a cell. Single-scattering distributions are first obtained from ice and protein by applying the Fourier-logarithmic deconvolution technique. The resulting reference spectra are then normalized by applying the Bethe sum rule to the differential oscillator strengths in order to derive the differential cross sections. A direct estimate of the water content can be obtained by applying a least squares fitting algorithm to spectra from hydrated specimens. Tests have been performed on thin cryosections of rapidly frozen bovine serum albumin standards, containing 70%, 80%, and 90% protein, by recording parallel-EELS spectra in the field-emission scanning transmission electron microscope (STEM). It was found that an accuracy of approximately 1% could be achieved in the determination of water content. The method has been applied to cryosectioned erythrocytes and cerebellar cortex.