2006-2007 - The Field Museum

SCANNING ELECTRON MICROSCOPE LABORATORY
The Field Museum’s two scanning electron microscopes (SEMs) are invaluable research tools for
examining fine surface details of three-dimensional objects and specimens from the museum’s
collections. The capability of viewing objects at very low magnifications as well as high magnifications
(over 100,000 times life-size) is one of the special features of our SEMs. Images obtained from the
scanning electron microscope achieve higher resolution and higher magnification than those observed
with light microscopy, and the SEM images also provide 300 times more depth-of-field than those
obtained with conventional light microscopy.
In addition to imaging, our newest SEM, the variable pressure LEO (now Carl Zeiss) EVO 60 Scanning
Electron Microscope, is equipped to analyze objects’ elemental composition with the Oxford INCA 350
Energy Dispersive X-ray Microanalysis System (EDS). This SEM was installed in April 2004 and has the
largest chamber available for viewing sizeable specimens and objects. The LEO/Zeiss SEM with the
Oxford EDS was generously funded by an anonymous donor and is part of the Museum’s Elemental
Analysis Facility.
The SEM Lab also has an Amray 1810 SEM that has been upgraded with a PC that has a digital imaging
capturing system. The Amray SEM is an excellent tool for very low magnification in addition to high
magnification work, examination without destructive methods (e.g. uncoated specimens), and a large
range of specimen movement and positioning. Specimen preparation instruments in the lab include a
Denton Vacuum Desk IV Sputter Coater (new purchase in 2006) for coating non-conductive specimens
with a thin layer of gold and a Balzers 030 Critical Point Dryer for drying soft tissue.
The SEM Laboratory is a multi-user research facility used by researchers and students in The Field
Museum’s Departments of Anthropology, Botany, Geology, and Zoology. The laboratory is managed by
Betty Strack. Twenty-five curators, graduate students (mostly from the University of Chicago and the
University of Illinois at Chicago), undergraduate interns, professional staff, research associates, and
international visiting/collaborating scientists from Collections and Research used the SEMs in 2006. The
staff, students, and collaborating scientists that had research projects include: Danny Balete, J.P. Brown,
Dave Clarke, Jochen Gerber, Ian Glasspool, Lance Grande, Larry Heaney, Eric Hilton, Brian Hockaday,
Michael Jorgensen, David Lentz, Greg Mueller, Link Olson, Kevin Pitz, Abigail Reft, Rebecca Rundell,
Brian Sidlauskas, Petra Sierwald, Julia Sigwart, Bill Turnbull, Xochitt Vinaja, Janet Voight, Andrew Wyatt,
Thomas Wesener, and William Whitehead.
Examples of recent and continuing research projects and specimens/ objects studied include:
• Anthropology conservation materials identification
• Ethnobotanical wood samples from Oaxaca, Mexico and from Guatemala
• Fungal spore morphology
• Sporangia of fossil fertile ferns
• Scale and teeth examination of fossil sturgeon
• Fossil mammal teeth
• Mammal teeth and skulls
• Fish (headstanding tetras) teeth
• Land snail shells
• Teeth of wood-boring clams
• Sensory organs on the siphons of clams
• Rove beetle morphology
• Photo atlas of millipede morphology
• Spider phylogeny
Two of the Museum’s 2006 exhibitions, Evolving Planet and Gregor Mendel: Planting the Seeds of
Genetics, have images from the LEO/Zeiss SEM on display.
116