The use of a microscope which is lit by a beam of light or electrons that has been refracted, diffracted, or condensed and diffused, so that only certain parts of the object being studied are lit while the rest of the field of view is dark. This technique is used to study tiny particles or organisms.

This technique is also referred to as dark field imaging, dark-field illumination, and dark-ground illumination.

---

From the BioTech Dictionary at http://biotech.icmb.utexas.edu/. For further information see the BioTech homenode.