Loeffler's Serum Medium I Purpose and Composition I Different types of Enriched Media, Culture Media

Описание: Loeffler’s Serum Medium is an enriched culture medium that accelerates the growth of Corynebacterium diphtheriae and enhances the formation of metachromatic granules, making it important in the diagnosis of diphtheria.
Purpose
It is an enriched medium used mainly for the cultivation of Corynebacterium diphtheriae.

Encourages the early growth and characteristic morphology of the bacteria.

Increases metachromatic granule formation (visible by special stains like Albert’s stain).

Helps differentiate C. diphtheriae from other throat flora.

Composition

Animal serum (horse or ox serum): provides growth factors and proteins.

Nutrient broth / beef infusion: supplies amino acids, vitamins, and minerals.

Glucose: energy source.

Eggs (sometimes): provide additional enrichment.

Serum is coagulated (heated) to solidify the medium, giving a slant-like surface for bacterial growth.

Advantages

Rapid growth of C. diphtheriae (within 6–8 hours).

Stimulates production of volutin/metachromatic granules.

Useful for morphological observation under the microscope.

Different Types of Enriched Media (Examples)

Blood Agar – intact RBCs, hemolysis detection.

Chocolate Agar – heated RBCs, releases X & V factors for Neisseria and Haemophilus.

Loeffler’s Serum Medium – enriched with animal serum, for Corynebacterium diphtheriae.

Löwenstein-Jensen Medium – egg-based, for Mycobacterium tuberculosis.

Brain Heart Infusion (BHI) Agar – supports many fastidious organisms.