Gram Stain Virtual Lab (Michigan State University)

http://learn.chm.msu.edu/vibl/content/gramstain/gramstain/index.html

1.    Read over the information in the “description” and “steps” tabs.

2.    Click the “start” tab to do the virtual lab. Be sure to do the “examine examples” at the end.

3.    Then, answer the following questions:

1.    What important step must happen before you can heat fix a slide?

2.    How long should your slide be passed through the flame when you heat fix it?

3.    Which liquid serves as the mordant?

4.    What color do Gram positive cells stain?

5.    What is an example of a Gram positive cocci found in clusters?

6.    What is an example of a Gram negative diplococci?

7.    What are some ways that one might end up with a false result? (Either Gram + that appears negative, or a Gram – that appears positive? Use your lab book for this.