Getting Set Up

1. Set the iris diaphragm to each objective lens and note setting. To set: remove eye piece and adjust to light 80% for each objective. Replace eye piece.
2. Coarse focus to 2-3 mm from slide and then slowly raise until image appears. Use fine focus to sharpen image.
3. Mirrors: Flat side for normal viewing, concave side for high power objectives and/or low light.
4. Lamps: If a halogen bulb is used and the light source is equipped with a rheostat always adjust to lowest setting before turning on and then increase light levels slowly.
5. 100 power objective lenses or higher require the use of immersion oil. Put a drop on top of the cover slip, lower objective into oil and rack away to focus.
6. Examining colorless parasites can be aided by using the diaphragm or filters to differentiate.

Slide Preparation

1. Put drop of tap water on slide, add material from scraping, then cover with cover slip by tipping it on to slide to minimize air bubbles. An air bubble will appear as a circle with a thick black wall and empty center when seen through the microscope.
2. To assist in viewing samples stains may be used.
   Mix I drop methylene blue to 5 ml of water and use one drop of this solution in place of tap water in slide preparation.
   Nigrosin is used for negative staining. Negative staining is used because the cell wall of live protozoa won’t allow the stain to penetrate. The protozoa stand out light on a black background. Add 1 drop nigrosin to material on slide and cover slip.
3. Use of "Protozoa Exam Liquid" can facilitate viewing fast moving protozoa like Trichodina. Add 1 drop to material and cover slip.
4. For examining Pond water or small fry use cavity slides.