Materials

  • Lab coat
  • Eye protection
  • Disposable gloves
  • Disinfectant and paper towels
  • Discard jar with disinfectant
  • Glass slide
  • Lens tissue
  • Wire loop
  • Labels
  • Small beaker
  • Nigrosin stain
  • Live yoghurt
  • Sterile water

Instructions

  1. Wear a lab coat, disposable gloves and use eye protection.
  2. Mix a little yoghurt with an equal quantity of distilled water in a beaker.

3. Flame a loop.

4. Place a loopful of the mixture at one end of a glass slide.

5. Flame the loop again.

6. Add one loopful of nigrosin stain and mix thoroughly using the wire loop.

7. Flame loop.

8. Prepare the film by dragging the yoghurt/stain mixture along the slide with the short edge of another slide. Do not fix with heat.

9. When absolutely dry, examine under oil immersion if possible. Otherwise, under x600 (x15 eyepiece, x40 objective).

10. When finished, dispose of slides into a discard jar.

Photomicrograph of yogurt