Question:easy
In nutrient agar, the concentration of agar is:
In nutrient agar, the concentration of agar is:
Show Hint
Standard solidifying concentration of agar in routine solid media.
Updated On: Jun 24, 2026
- 1%
- 1.5%
- 3%
- 4%
Show Solution
The Correct Option is B
Solution and Explanation
Step 1: Solid culture media are made by gelling a liquid broth with agar, a seaweed polysaccharide that sets the surface for colony growth without feeding the microbes.
Step 2: For standard nutrient agar the recipe fixes the agar at 1.5% added to nutrient broth, giving a firm plate suitable for streaking and isolation.
Step 3: The nutritive part of the broth supplies peptone near 0.5%, meat or yeast extract near 0.3% and salt near 0.5%, balanced to neutral pH around 7.4.
Step 4: A 1% concentration leaves the medium too soft, while 3% or 4% overgels it without benefit, so the routine working figure is 1.5%.
\[\boxed{1.5\%}\]
Step 2: For standard nutrient agar the recipe fixes the agar at 1.5% added to nutrient broth, giving a firm plate suitable for streaking and isolation.
Step 3: The nutritive part of the broth supplies peptone near 0.5%, meat or yeast extract near 0.3% and salt near 0.5%, balanced to neutral pH around 7.4.
Step 4: A 1% concentration leaves the medium too soft, while 3% or 4% overgels it without benefit, so the routine working figure is 1.5%.
\[\boxed{1.5\%}\]
Was this answer helpful?
0
