Dark background microscope
The dark background microscope is a light microscope used to increase contrast of transparent objects.
Dark background microscopy technique
The dark background microscope can improve the contrast of samples which are transparent a priori and difficult to see under a conventional light microscope. The light source (transmitted) does not directly reach the lens: only the light which is diffused and therefore deviated by the sample is seen. Contrast is therefore greatly improved without the need to stain a transparent sample. Sample preparation is therefore not difficult although this benefit is counted by the low light intensity seen by the observer
Use of the dark background microscope
The dark background microscope is suitable for unstained samples. It can be used to observe living structures such as bacteria or unicellular organisms.
Appearance of a water flea seen under a dark background microscope © Nebarnix, CC by-nc-nd 2.0