Inside bacteria

In 1930's the electron microscope was invented. This uses a beam of electrons to magnify specimens up to 2 000 000 times. 

Electron microscopes also produce very clear images and have helped to discover much more about the detailed structure of cells.

• For example, light microscopes show that bacteria do not have nuclei. 
• Electron microscopes show that microscopes show that bacterial cells contain two types of DNA. 

Chromosomal DNA is a giant loop of DNA…