Scientific instruments have opened up sensory domains far beyond the constraints of biological perception. Technology has extended our phenotype enormously and has pushed the boundaries of what can be known...
A soybean cyst nematode and its egg. 1000X Low-temperature scanning electron micrograph. Source: Electron Microscope Units ARS, Beltsville, Maryland.
3010 TEM. Photo source: Materials Research Facilities Network (MRFN)
Chloroplast TEM from Department of Botany Instructional Technology, University of Wisconsin-Madison website
Scanning and Transmission electron microscopes provide magnifications of up to two million times. The resolution of two-dimensional TEM sections is greater than SEM images formed by rastering electron beams across specimen surfaces. Samples for electron microscopy are freeze-dried and stained with heavy metals. They are viewed in a vacuum. Preparation techniques can damage delicate biological samples or give rise to artifacts.
