PREPARATION OF WET MOUNT SLIDE
Professor of Biology and Chemistry
University of Cincinnati Clermont College,
Batavia OH 45103
10 July 1989, rvsd 2 July 1993, 10 July 1995, 3 July '97, 28 June 01
This page has been accessed times since 19 July 2002.
Wet mount preparations are especially valuable for demonstrating motility in microorganisms. Fresh cultures must be used for maximum motility. No stain is employed since most stains kill the organisms (except vital stains). Therefore focusing is more difficult (see step 4 for suggestions). If your microscope has dark field capabilities, this is ideal illumination for this purpose (use the "D" position on the sub-stage condenser dial). Alternatively, a small disc of dark paper may be placed in the center of teh condensor to approximate dark field optics.
Motility needs to be distinguished from Brownian motion which is due to molecular bombardment. Brownian motion occurs in all microscopic bodies suspended in water and appears as a random shimmying-shaking. Motility will be in the form of cork-screw spiraling, movement in a given direction, or tumbling in place.
Wet mount preparations are also useful
for giving clear images of fresh specimens under the microscope. Features
which may be particulate, such as spores of fungi and ferns, and pollen
grains may be best observed using this technique.