Edwards Medium Base, Modified – Selective Agar for Streptococcus agalactiae Isolation, 250g

Edwards Medium Base, Modified is a selective medium formulated for the isolation and differentiation of Streptococcus agalactiae (Group B Streptococcus, GBS) from clinical and veterinary samples. The addition of thallium sulfate enhances selectivity by inhibiting unwanted flora, while supplementation with 5–7% sterile defibrinated sheep blood improves detection through hemolytic reaction.

Key Features:

• Designed for Group B Streptococcus isolation

• Requires supplementation with 0.33 g/L thallium sulfate

• Enriched with 5–7% sterile defibrinated sheep blood for optimal results

• Recommended for use in clinical, diagnostic, and veterinary microbiology laboratories

Composition (per liter):

• Lab-Lemco’ powder (Beef Extract) ………. 10.0 g

• Peptone ………………………………. 10.0 g

• Aesculin (Esculin) …………………….. 1.0 g

• Sodium Chloride ……………………….. 5.0 g

• Crystal Violet ………………………… 1.3 mg

• Agar ………………………………….. 15.0 g

• Final pH: 7.4 ± 0.2 (25℃)

Preparation Instructions:

1. Suspend 41.0 g of Edwards Medium Base, Modified in 1 liter of distilled or deionized water.

2. Add 0.33 g of thallium sulfate.

3. Heat to boiling with frequent agitation until completely dissolved.

4. Dispense into containers.

5. Sterilize by autoclaving at 115℃ for 20 minutes.

6. Shake well after sterilization to prevent agar sedimentation.

7. Cool to 50℃ and aseptically add 5–7% sterile defibrinated sheep blood (or horse blood).

8. Mix thoroughly and pour into sterile Petri dishes.

Storage:

• Store in a cool, dry place at room temperature.

• Shelf life: 3 years.