- Explain why gram + bacteria stain purple, what happens during the decolorization step, and why Gram-cells stain pink.
- What is the function of the Iodine step?
- Were you able to distinguish between G+ cells and G- cells? Give the gram reactions of E. coli and S. saprophyticus.
- Why is the acetone/alcohol step the most critical step in the process?
- If you observed bacteria from a single colony that were gram variable,
- What other characteristics could you use to help you identify the organism?
- How might the age of the culture affect the results?
- What would happen if you Gram stained E. coli, but forgot the decolorizing step?
- What would happen if you Gram stained S. saprophyticus and forgot the decolorizing step?
- Explain, in your own words and experience, whether or not your smear prep was done appropriately for this stain.
Contributors and Attributions
Kelly C. Burke (College of the Canyons)