nutrient agar

Thân thiện

A scientist pours nutrient agar into a petri dish.

Definition

Noun: A solid, gel-like substance used in laboratories to grow microorganisms such as bacteria and fungi. It is made by combining a nutrient broth with agar, a gelatinous material derived from seaweed, which solidifies the mixture to provide a stable surface for microbial growth.

Usage

"Nutrient agar" is a compound noun. It refers specifically to the prepared, solidified growth medium. It is typically used as a mass noun (e.g., "poured nutrient agar") but can be counted when referring to specific plates or batches (e.g., "prepare three nutrient agars").

Examples

• The microbiologist sterilized the nutrient agar before pouring it into Petri dishes.
• This bacterium forms distinctive yellow colonies on nutrient agar.
• We need to check if the sample grows on standard nutrient agar.

Advanced Usage

• Selective/Differential Media: While basic nutrient agar supports the growth of many microorganisms, the term is often the base for more specific media. For example, "blood agar" is nutrient agar supplemented with blood.
• In Research Protocols: Instructions often specify "on nutrient agar" to describe the standard solid medium for routine cultivation, as opposed to liquid "nutrient broth."

Variants and Related Words

• Agar (noun): The gelling agent itself, derived from red algae.
• Nutrient broth (noun): The liquid form of the growth medium without the agar solidifying agent.
• Culture medium (noun): The general term for any substance used to support microbial growth; nutrient agar is a type of solid culture medium.
• Plate (noun, in lab context): Often used informally to refer to a Petri dish containing nutrient agar (e.g., "streak the plate").

Synonyms

• Growth medium (general synonym)
• Agar medium (broader synonym, as other agars exist, e.g., Sabouraud agar)
• Solid medium (descriptive synonym contrasting with liquid broth)

Related Phrases/Idioms

No common idioms or phrasal verbs are associated with this specific technical term.

Học thuật

Noun

1. any culture medium that uses agar as the gelling agent

Từ đồng nghĩa

• agar