Agar Base No. 2
Also known as：Blood Agar Base No.2 · Blood Agar Base
For the cultivation of fastidious microorganisms and, with the addition of blood, for the determination of haemolytic reactions, including the haemolysis test for Listeria species.
- Category
- Dehydrated Culture Media
- Dissolve per litre
- 42.5 g
- Pack sizes
- 500 g · 5 kg · 25 kg
- Certifications
- ISO 22000
Data updated：2026-11-06
Overview
Principle
Agar Base No. 2 is a highly nutritious medium that, supplemented with blood, supports the growth of fastidious organisms and allows clear observation of haemolytic reactions. Proteose peptone, liver extract, and yeast extract supply nitrogen, amino acids, vitamins, and growth factors, and sodium chloride maintains the osmotic equilibrium. The medium supplemented with sheep blood is used in the confirmation of Listeria species, where Listeria monocytogenes produces a narrow, clear zone of beta-haemolysis that distinguishes it from non-haemolytic species such as Listeria innocua.¹ʼ² The haemolytic zone may be faint and is best observed under bright transmitted light after removal of the colony.
Directions
Suspend 42.5 g of powder in 1 L of purified water. Heat with continuous stirring and bring to the boil for 1 minute. Sterilize by autoclaving at 121°C for 15 minutes. Cool to 45-50°C and aseptically add 5-7% defibrinated sheep blood. Mix well and pour into sterile Petri plates. Test the finished medium for performance using stable, standard control cultures.
Cultural response
| Test organism | ATCC | Growth |
|---|---|---|
| Listeria monocytogenes | 13932 | good-luxuriant |
| Listeria innocua | 33090 | good-luxuriant |
| Staphylococcus aureus | 25923 | good-luxuriant |
| Streptococcus pyogenes | 19615 | good-luxuriant |
Product highlights
- Food-grade raw materials, produced in an ISO 22000 certified facility
- Manufactured to the standard formulation, 42.5 g per litre
- Performance verified against standard control strains before release (Listeria monocytogenes, Listeria innocua, Staphylococcus aureus, Streptococcus pyogenes)
- Available in 500 g / 5 kg / 25 kg, from laboratory to industrial scale
- COA, specification sheet, and technical data sheet available; samples on request
- Manufactured in Taiwan with reliable supply
Food grade versus laboratory grade
Most culture media suppliers use laboratory-grade raw materials, which are held to lower standards for heavy metal residues, microbial contamination control, and traceability. That is adequate for pure research but not for applications with stricter raw-material requirements. STBIO manufactures with food-grade raw materials throughout, in a facility certified to ISO 22000 food safety management.
- Food microbiology laboratories working to ISO 17025 or equivalent requirements
- Biotech manufacturers exporting fermentation products and needing full raw-material traceability
- Organisations with ESG or compliance audit requirements across their supply chain
- Companies sourcing both Halal and non-Halal products who need one consistent material grade
Frequently asked questions
01How much powder per litre?
Use 42.5 g per litre of deionised water; preparation and sterilisation conditions are given on the specification sheet.
02Which organisms is it suitable for?
Pathogens, Gram-positive, Listeria, Listeria monocytogenes, Listeria innocua, Staphylococcus aureus, Streptococcus pyogenes. See the cultural response table and the specification sheet.
03Can it be used for food-grade applications?
Yes. It is made from food-grade raw materials in an ISO 22000 certified facility and is suitable for culturing starters for fermented products that are consumed directly.
04How is this product prepared?
Suspend 42.5 g of powder in 1 L of purified water. Heat with continuous stirring and bring to the boil for 1 minute. Sterilize by autoclaving at 121°C for 15 minutes. Cool to 45-50°C and aseptically add 5-7% defibrinated sheep blood. Mix well and pour into sterile Petri plates. Test the finished medium for performance using stable, standard control cultures.
05How do I request a bulk quotation, and can you provide a COA?
Yes. This product is available in 500 g, 5 kg, 25 kg. Tell us your application and volume when requesting a quotation; we reply within one working day and can supply the COA, specification sheet, and technical data sheet.
References
- 1. ISO 11290-1, Microbiology of the food chain — Horizontal method for the detection and enumeration of Listeria monocytogenes and of Listeria spp. — Part 1: Detection method, International Organization for Standardization, Geneva.
- 2. ISO 11290-2, Microbiology of the food chain — Horizontal method for the detection and enumeration of Listeria monocytogenes and of Listeria spp. — Part 2: Enumeration method, International Organization for Standardization, Geneva.