Gram Staining

Question 1

What is Gram Staining?

Answer 1

A method of staining bacteria that allows us to see if a Bacterial cell is Gram positive or Gram negative.

Question 2

What is the Purpose of Gram Crystal violet in the process of Gram Staining?

Answer 2

This stains all bacteria Purple.

Question 3

What is the purpose of Gram iodine in the process of Gram staining?

Answer 3

Fixes the dye to the bacterial cells

Question 4

1) What is the purpose of Ethanol in Gram staining?

2) Why doesnt The Ethanol affect Gram positive bacteria?

Answer 4

1) Breaks down the Cell Walls to release the dye from the Gram negative bacteria.

2) The Cell wall on Gram possitive bacteria is much thicker so doesnt get fully broken down meaning the purple dye is not released.

Question 5

What is the purpose of Gram Safranin in the process of Gram staining?

Answer 5

Stains the unstained bacteria(the Gram negative) and will darken the purple stained bacteria(the Gram Positive).

Question 6

What is the purpose of Gram Safranin in the process of Gram staining?

Answer 6

Stains the unstained bacteria(the Gram negative) and will darken the purple stained bacteria(the Gram Positive).

Question 7

a) What are the physical diffrences between the Gram positive and Gram negative bacteria?

b) What colour do the Positive/Negative bacteria go when staineing is completed?

Answer 7

1a) Positive – One Cell Membrane and a thick Cell Wall.
1b) Purple

2a) Negative – Two Cell Membranes and a thin Cell Wall.
2b) Red