EM 006 Fibroblast

Transmission Electron Microscopy

Ultrathin section of a fibroblast as seen by transmission electron microscope (TEM). Examine the ultrastructure of this spindle-shaped cell:

• Plasma Membrane
• Nucleus
  • Nucleolus is not visible
• Golgi Apparatus
  • Stacks of membranes surrounded by vesicles
• Mitochondria
  • Many cisterna are seen within the mitochondria
• Endoplasmic Reticulum
  • Ribosomes on its surface indicate this is rough endoplasmic reticulum
• Cytoplasm (green)

False Color

The human eye can distinguish only a limited number of grayscale values but can distinguish between millions of colors. So more information can often be extracted from color images. Thus, pseudo-coloring can be helpful in improving the interpretation of grayscale images.

This image has been colored to highlight the ultrastructure of this cell. The false-colored image is displayed by selecting the “Color” option beneath the image shown above.

Examine the ultrastructure of this spindle-shaped fibroblast:

• Plasma Membrane (dark green)
• Nucleus (blue) / Nuclear Envelope (purple)
• Golgi Apparatus (yellow)
• Mitochondria (red)
• Rough Endoplasmic Reticulum (cyan)
• Cytoplasm (green)

Magnification

Because of the wide range of magnifications possible with electron microscopy, it is often difficult to appreciate the size of objects in a micrograph.

Two approaches are usually used to indicate scale:

• Magnification Value: the ratio between size of object on a picture and its real size. Because it depends on the final size of the picture, it is only useful with print images.
• Scale Bar: a bar of known length is displayed on a picture. Because it is resized when the size of a picture is changed, it is useful with digital images.

A scale bar is shown in the lower left corner. Its length is automatically adjusted as the image is zoomed in or out. In addition, the total size of the view is shown in the right side of the toolbar.

Estimate the length of the fibroblast: [ + ]