Virtual SEM of a diatom
There’s more to life than meets the eye…
To prepare this piece of seaweed for SEM it has first been dried thoroughly, attached to a brass stub and coated with a very thin layer of gold. The sample is then bombarded with electrons which are deflected by the gold coating to create an image that can be photographed.
Increase the magnification until you can see the details of the ornamentation inside the diatom at a magnification of x 16,000.
Diatoms like these are found throughout the world in both salt and fresh water. In the Antarctic they form an important part of the food web.
To use the Virtual SEM:
- Turn on the SEM (blue Power button).
- Adjust the brightness and contrast (about mid-way).
- Adjust the focus of the image (near Max).
- Use the Magnification's min and max buttons to magnify the image.
NB. Move the sliders slowly. The SEM is a delicate instrument!
The Virtual Scanning Electron Microscope requires the QuickTime plug-in, which is available from Apple’s web site.
If you cannot use QuickTime to view the Virtual SEM, the Electron microscopy section gives a good overview of how we use our instruments.
