Visualization of dendrimer molecules by transmission electron microscopy (TEM): Staining methods and Cryo-TEM of vitrified solutions
Visualization of dendrimer molecules by transmission electron microscopy (TEM): Staining methods and Cryo-TEM of vitrified solutions
复制标题
DOI：
10.1021/ma9806155
复制
发表时间：
1998-09-08
期刊：
影响因子：
5.5
通讯作者：
Amis, EJ
中科院分区：
文献类型：
--
作者：
Jackson, CL;Chanzy, HD;Amis, EJ
用磷钨酸钠水溶液染色后，通过常规透射电子显微镜 (TEM) 对第 10 代 (G10) 至 G5 的聚酰胺胺 (PAMAM) 的各个树枝状聚合物分子进行成像。树枝状聚合物被解析为单独的、光束稳定的实体，并对它们的尺寸和尺寸分布进行统计分析，并与溶液中小角度 X 射线散射的数据进行比较。水性 G10 树枝状聚合物还通过在液体乙烷中骤冷 (cryo-TEM) 后冷冻、水合状态下的检查进行表征，并将数据与染色实验的结果进行比较。对于第一近似，树枝状聚合物在投影中呈现圆形，并且直径符合高斯分布，该分布随着代数的增加而稍微变宽。一般来说，冷冻透射电镜证实了染色实验，但表明在天然状态下，树枝状聚合物的形状存在更多变化，多面体形状经常出现。
Individual dendrimer molecules of poly(amidoamine) (PAMAM) from generation 10 (G10) to G5 were imaged by conventional transmission electron microscopy (TEM) after staining with aqueous sodium phosphotungstate. The dendrimers were resolved as separate, beam-stable entities, and their sizes and distribution of sizes were statistically analyzed and compared with data from small-angle X-ray scattering in solution. Aqueous G10 dendrimers were also characterized by examination in the frozen, hydrated state after quench-freezing in liquid ethane (cryo-TEM) and the data compared with the results of the staining experiments. To a first approximation, the dendrimers appeared circular in projection and the diameters conformed to a Gaussian distribution which broadened somewhat with increasing generation number. Cryo-TEM, in general, confirmed the staining experiments but suggested that, in the native state, there is more variability in the shapes of the dendrimers, with polyhedral shapes occurring quite frequently.