EM Home
Contact Info
EM Overview
EM Courses
Reference Links
EM Library



BIOLOGY 210 - Scanning Electron Microscopy

[Go to semester: Fall 2002, Fall 2003, Spring 2005, Spring 2006]

The scanning electron microscope (SEM) is used to teach principles of electron optics and digital imaging for the study of surface morphology and microstructure of materials. The following micrographs were captured by students in BIOL 210.

(below, left) A close view of a butterfly wing. (Anthony Belanger '03)
(below, right) Another view of the complex, delicate scales of a butterfly wing. (Jen Petzold '03)

(below, left)
A view of villi in a mouse duodenum. (Peter Bittenbender '03)
(below, right) A lateral view of the internal structure of individual villi, revealing a core of connective tissue surrounded by a layer of epithelial cells. (Lilia Zhahalyak IDP)

(below) A look at the intricate structure of a fish gill. (Peter Bittenbender '03)

The following three images of fish gill showcase some of the effects of manipulating the SEM's operating parameters. In this progression of images, the resolution of the object in the foreground is improved; depth of focus is also affected as indicated by the arrow marker. All micrographs taken by Jen Petzold '03.
(below, left)
Large working distance, small aperture (longest depth of focus).
(below, center) Short working distance, larger aperture.
(below, right) Short working distance, small aperture (best foregound image resolution).
(below, left) A view of murine liver revealing highly geometric hepatocytes separated by small channels called bile canaliculi. (Amy Johnson '03)
(below, right) A closer look at a single bile canaliculus. (
Amy Johnson '03)

(below) Fine structure of a Lilium pollen grain. (Anthony Belanger '03)