Serial dilutions

Question 1

Series of sequential dilutions that are performed to convert a dense solution into a

Answer 1

more usable concentration.

Question 2

How are serial dilutions done

Answer 2

Done step by step, taking a bit from the previous dilution and putting it into freshwater or broth to further dilute it

Question 3

What are serial dilutions done for?

Answer 3

• Standard curves
• Prepare a series of concentrations for an experiment
• Estimate the number of cells in a liquid culture

Question 4

List the procedure for the gram-stain

Answer 4

1) Gently stain with crystal violet for 1 minute

2) Gently wash off the stain with tap water

3) Gently apply Gram’s iodine for 1 minute

4) Gently wash off the Gram’s iodine

5) Add 95% alcohol drop by drop until the alcohol runs almost clear

6) Gently wash off the 95% alcohol with tap water

7) Counterstain with safranin for 45 seconds

8) Gently wash off the safranin with tap water

9) Blot dry with bibulous paper