Questions on Gram staining - (May/10/2008 )

I am really having a hard time grasping Gram staining.

Can anyone assist me with this?

In a Gram stain, one step could be omitted and still allow differentiation between gram-positive and gram-negative cells. What is that one step and how will the two categories of bacteria appear?

---

I wouldn't suggest omitting any step from the gram staining procedure as the entire process takes less than 5 minutes. If you need an answer for conceptual purposes for a class, I would say the initial stain with crystal violet can be omitted. By doing so, gram positive bacteria should appear colorless/unstained, whereas gram negative cells would appear light pink from only taking up the basic fuscion or safranin counterstain from the last step.

---

Thanks for the reply. I read somewhere that "counterstain" might be the only one....is that what you were referring to above?

---

[/quote]
Thanks for the reply. I read somewhere that "counterstain" might be the only one....is that what you were referring to above?
[/quote]



According to a text book diagram I have, both of us would be correct. Omitting the final counterstain would leave gram negative bacteria colorless and the gram positive's purple.

---