Materials

  • Lab coat
  • Eye protection
  • Disposable gloves
  • Benchkote if necessary
  • Disinfectant and paper towels
  • Discard jar with disinfectant
  • Fibre free blotting paper
  • Labels
  • Forceps
  • Staining rack and dish
  • Distilled water bottle
  • Methylene blue stain
  • Fixed smears of bacteria or yeast

Instructions

  1. Wear a lab coat, disposable gloves and use eye protection.
  2. Place the fixed smears of bacteria on a staining rack over a sink or staining tray (pie dish).
  3. Flood with methylene blue and leave for 2 minutes.
  4. Hold the slide at a 45 angle over the sink or staining tray, use the wash bottle to rinse the smear well with water.
  5. Blot dry between two layers of fibre free blotting paper, taking care not to rub off the cells and allow to dry in air.
  6. Examine under oil immersion if possible. Otherwise, under x600 (x15 eyepiece, x40 objective).
  7. Record shape (rod, spherical or spiral) and arrangement (clusters, chains or pairs) of the bacteria examined.
  8. When finished, dispose of slides into discard jar.

N.B. This method can be used for other simple stains.

Saccharomyces cervisiae

x160                                                                                                                                 x400