A wet mount uses a liquid mounting medium, in most cases water. It is also possible to make a wet mount using pure glycerine. Wet mounts are temporary in nature and can not be stored over extended time periods.
A wet mount is probably one of the most universal ways of preparing a slide. The organism should still meet these criteria:
- The organism must be sufficiently thin. Otherwise it is not possible to place it between slide and cover glass. Water fleas and other similar creatures can be viewed by placing a spacer beneath the cover glass.
- The organism should have a refractive index which is different from that of the mounting medium (i.e. water). Bacteria have a similar refractive index and are therefore difficult to see, unless one uses DIC or phase contrast methods.
- The organism should have a color but should not be opaque. It should allow light to pass through. Otherwise one is only able to see a dark shadow.
- The organism’s natural habitat should be compatible with the mounting medium. For example, if you attempt to view salt water organisms, then it may not be a good idea to use fresh water for making the wet mount. This may damage the organism.
This post is in response to a reader’s question.