h Akbarzadegan
h Shahbazy - shahbazy.h@gmail.com

In 1931, while conducting research for his masters at the Technical College of Berlin, Ernst Ruska and Max Knoll design the first Transmission Electron Microscope (TEM). The initial designs were able to magnify specimens up to seventeen times greater than that of a light microscope; modern designs have a resolution at most of 10,000 times greater. One of the major historical limitations of TEM was that electrons were largely unable to pass through thick specimens; until the diamond knife and ultra -microtome were designed in 1951 it was largely impossible to utilize this instrument to full capacity. While the theoretical upper limit of the transmission electron microscope is estimated to be as high as 10,000 times that of a light microscope, flaws in the equipment used lowers the real limit.Combined with difficulty in preparing specimens, it is realistically only possible toresolve an object to about 0.025nm. A light microscope, in contrast, can resolve an object to about 2nm at maxium resolution