Plant Pathology: Extension: Plant Disease Library

A wet mount is the technique of placing small section of infected tissue in a droplet of water for viewing with the compound microscope.

1. Place a drop of water on a glass slide.
2. Using the stereo microscope, focus on the fungal fruiting structures. Cut out a small section of the tissue containing the structures using a scalpel or pick off individual structures with a dissecting needle. Small sections of the affected tissue can be cut out without the aid of the stereoscope, but success will vary from person to person and sample to sample. Do not cut out too large a section because you will not be able to view it clearly on the compound microscope.
3. Place the cut out section in the water droplet.
4. Cut out several pieces and place all within the same water droplet. This will increase your chance of clearly viewing the fungus with the compound scope.
5. Gently place a cover slip over the water droplet. Place one side of the cover slip against the water droplet and gently let the cover slip fall over the droplet.
6. Gently tap the cover slip with the blunt end of the dissecting needle or scalpel to remove air bubbles if present.