Simple Stain Lab

Purpose:

To teach the student the techniques involved in doing a simple stain.

To show the three morphological types of bacteria.

Materials:

Cultures (agar slants).

Micrococcus luteus.

Bacillus subtilis.

Rhodospirillum rubrum.

Dyes.

Safranin.

Methylene blue.

Gentian violet. (Crystal violet)

Staining rack.

Glass slides.

Procedure:

1. Clean three slides. Handle only at edges. Mark with name of cultures to be used.

2. Place a single drop of water in the center of each slide.

3. Flame the needle.

4. Remove a small amount of the growth using aseptic technique. DO NOT DIG INTO THE AGAR.

5. Flame and close the culture tube. Return to rack.

6. Mix the small sample of culture with the water on the slide.

7. Flame the needle. Repeat with another culture on slide 2 and the third culture on slide 3.

REMEMBER TO FLAME NEEDLE THOROUGHLY BETWEEN EACH TRANSFER.

8. Allow the films to air-dry completely.

9. Pass each of the slides through the flame about three times to heat fix.

10. Place the "fixed" slides on staining rack over sink and apple one of the dyes to each specimen using the following time intervals.

Slide 1-safranin (two minutes).

Slide 2-methylene blue (three minutes).

Slide 3-gentian violet (one minute).

(crystal violet)

11. Wash each slide in tap water.

12. Blot to dry.

13. Slides are now ready to examine under the low, high-dry, and oil immersion objectives.

IV. Daily Diary:

The members of my group were: Lyndsey Hensel, Brooke Brown, Lauren Hathaway, and I. We took all of our slides we made from our last slide preparation lab, and used them to stain. While placing them on the staining rack our group members assembled the three different dyes, safranin,