Endospore stain

Purpose

To determine endospore formation in gram postive bacteria

Materials

• Sterile water
• Microscope slide
• Microscope with 40X
• 5% (w/v) malachite green solution
• 0.5% (w/v) safranin solution

Instructions

1. On a microscope slide, suspend bacteria in a drop of water
2. Let air dry
3. Stain with malachite green solution for 10 minutes
4. Rinse thoroughly with water and dry briefly
5. Counter stain with safranin solution for 15 seconds
6. Rinse thoroughly with water and blot dry
7. Look at cells under 40X

Results

• Bacterial cells stain red
• Endospores stain green

References

• Schaad, N.W. 2001. Laboratory Guide for the Identification of Plant Pathogenic Bacteria, 3rd Edition. The American Phytopathological Society, St. Paul, MN. (pp 6, 9)

Contributed by

From the University of Florida Plant Disease Clinic-GNV System Manual: originally created by Anne Vitoreli; contributed by Anne Vitoreli.