Faculty of Health Sciences, Department of Anatomy, School of Medicine, University of Pretoria, South Africa.
Microsc Res Tech. 2010 Mar;73(3):225-8. doi: 10.1002/jemt.20778.
Scanning electron microscopy (SEM) is used to view a variety of surface structures, molecules, or nanoparticles of different materials, ranging from metals, dental and medical instruments, and chemistry (e.g. polymer analysis) to biological material. Traditionally, the operating conditions of the SEM are very important in the material sciences, particularly the acceleration voltage. However, in biological sciences, it is not typically seen as an important parameter. Acceleration voltage allows electrons to penetrate the sample; thus, the higher the acceleration voltage the more penetration into the sample will occur. As a result, ultrastructural information from deeper layers will interfere with the actual surface morphology that is seen. Therefore, ultimately, if acceleration voltage is lower, a better quality of the surface molecules and structures will be produced. However, in biological sciences, this is an area that is not well-documented. Typically, acceleration voltages of between 5 and 20 kV are used. This manuscript investigates the influence of acceleration voltages ranging from 5 kV to as low as 300 V, by studying surface ultrastructure of a human platelet aggregate. It is concluded that, especially at higher magnifications, much more surface detail is visible in biological samples when using an acceleration voltage between 2 kV and 300 V.
扫描电子显微镜（SEM）用于观察各种不同材料的表面结构、分子或纳米颗粒，范围从金属、牙科和医疗仪器以及化学（如聚合物分析）到生物材料。传统上，SEM 的操作条件在材料科学中非常重要，特别是加速电压。然而，在生物科学中，它通常不被视为一个重要参数。加速电压允许电子穿透样品；因此，加速电压越高，穿透样品的深度就越大。结果，来自更深层的超微结构信息会干扰实际观察到的表面形态。因此，最终，如果加速电压较低，就会产生更好质量的表面分子和结构。然而，在生物科学领域，这方面的文献记录并不完善。通常，使用的加速电压在 5 到 20 kV 之间。本文通过研究人类血小板聚集物的表面超微结构，研究了加速电压范围从 5 kV 到低至 300 V 的影响。结论是，特别是在更高的放大倍数下，在生物样本中使用 2 kV 至 300 V 之间的加速电压时，表面细节更为明显。
