Blood Agar Base No. 2

Blood Agar Base No. 2

Highly Enriched Medium for Superior Haemolysis
Catalog Number: AS-1145

Overview

Blood Agar Base No. 2 (CAT: AS-1145) is a premium, non-selective solid culture medium base formulated to produce exceptionally wide, sharp, and well-defined haemolytic zones when supplemented with 5–10% sterile defibrinated blood (sheep or horse).

Its enriched formulation—containing meat infusion, liver digest, selected peptones, and yeast extract—supports luxuriant growth of fastidious organisms and enhances haemolysin expression. This makes Blood Agar Base No. 2 particularly well suited for β-haemolytic streptococci, where haemolysis clarity is critical for accurate interpretation. It is widely regarded as superior to standard blood agar bases in both clinical and veterinary microbiology laboratories.

Key Features & Benefits

• Produces wide, clear β-haemolysis zones, especially with Streptococcus pyogenes

• Extra-rich nutrient base for fastidious and haemolytic organisms

• Transparent agar surface for easy colony and haemolysis observation

• Ideal base for blood agar, chocolate agar, and CAMP test media

• Performance comparable to leading international reference formulations

Typical Applications

Clinical & Veterinary Microbiology

• Primary isolation of β-haemolytic streptococci (Groups A, B, C, G)

• Differentiation of α-, β-, and γ-haemolysis patterns

Fastidious Organism Cultivation

• Streptococcus pneumoniae

• Listeria monocytogenes

• Corynebacterium spp.

• Neisseria spp.

• Haemophilus spp. (after chocolate agar preparation)

Specialised Testing

• CAMP test

• Preparation of chocolate agar

• Base medium for selective streptococcal formulations

Composition (per litre)

• Proteose Peptone: 15.0 g

• Liver Digest: 2.5 g

• Yeast Extract: 5.0 g

• Meat Infusion (equivalent): 10.0 g

• Sodium Chloride: 5.0 g

• Agar: 14.5 g

Final pH: 7.4 ± 0.2 at 25 °C

Supplementation

• Add 5–10% v/v sterile defibrinated blood (50–100 mL/L)

• Sheep or horse blood recommended

• Add at 45–50 °C to preserve red cell integrity

Preparation

1. Suspend 52.0 g of dehydrated medium in 1 L purified water

2. Heat with agitation and boil until fully dissolved

3. Autoclave at 121 °C for 15 minutes

4. Cool to 45–50 °C

5. Aseptically add 5–10% sterile defibrinated blood with gentle mixing

6. Pour plates immediately (≈20 mL per 90 mm plate)

Typical Haemolysis (24 h at 35–37 °C, 5% CO₂)

• Streptococcus pyogenes: very wide, clear β-haemolysis (often >10 mm)

• Streptococcus agalactiae: narrow or double-zone β-haemolysis

• Streptococcus pneumoniae: α-haemolysis (green)

• Listeria monocytogenes: narrow β-haemolysis

Storage & Stability

• Dehydrated medium: Store below 30 °C, dry and sealed

• Prepared blood agar plates: Store at 2–8 °C, protected from drying

• Recommended shelf life (plates): 3–4 weeks, depending on blood source

Intended Use

For laboratory and veterinary microbiology use only.
Not intended for therapeutic or direct human administration.

Quality & Compliance

• Suitable for regulated clinical and veterinary laboratories

• Consistent batch-to-batch performance

• COA and SDS available upon request