ISP Medium 2 (AS-1211) | Yeast Malt Extract Agar for Actinomycetes
ISP Medium 2
Yeast Malt Extract Agar for Streptomyces Morphology & Pigment Characterization
The classical ISP taxonomy medium for observing colony development, aerial mycelium, substrate mycelium, and pigment formation in Streptomyces and related actinomycetes.
Taxonomy Workhorse
Overview
ISP Medium 2, usually referred to as Yeast Malt Extract Agar, is one of the best-known media in the International Streptomyces Project system and is widely used for cultivation and taxonomic characterization of actinomycetes. In modern Streptomyces work it is especially valued for observing colony morphology, pigment production, and aerial mycelium development. citeturn421530search0turn421530search6turn421530search14
ATCC handling information for multiple Streptomyces strains specifically references ISP Medium 2 as a standard agar for culture recovery and maintenance following inoculum preparation in ISP Medium 1. citeturn421530search1turn421530search11turn421530search15
Because of its balanced nutrient composition and reliable plate morphology, ISP 2 is often the first solid medium used when comparing actinomycete isolates in a taxonomic set.
Typical Composition (per Liter)
| Ingredient | Concentration | Role |
|---|---|---|
| Yeast extract | 4.0 g | Vitamins and growth factors |
| Malt extract | 10.0 g | Carbon source and nutritive complexity |
| Dextrose / glucose | 4.0 g | Readily available carbon source |
| Agar | 15.0–20.0 g | Solidifying agent |
Original and reference sources commonly cite yeast extract 4 g/L, malt extract 10 g/L, glucose/dextrose 4 g/L, with pH around 7.0–7.3 before sterilization. citeturn421530search0turn421530search6turn421530search14
Applications
- Observation of aerial mycelium and substrate mycelium
- Pigment and colony morphology characterization
- Routine maintenance and taxonomy of Streptomyces isolates
- Comparative characterization across ISP medium sets
ISP Taxonomy Comparison
| Medium | Main Use | Diagnostic Value |
|---|---|---|
| ISP 2 | Morphology and pigment | Core reference plate for taxonomy |
| ISP 3 | Oatmeal-based sporulation | Additional colony character and sporulation data |
| ISP 4 | Starch utilization | Biochemical differentiation |
Technical Specifications
| Cat. No. | AS-1252 |
| Medium Type | Agar |
| Preparation | Approx. 38–39 g/L |
| Final pH | 7.0–7.3 |
| Sterilization | 121°C for 15–20 minutes |
| Primary Use | Morphology and maintenance |
Preparation Protocol
- 1Suspend the required amount in purified water.
- 2Heat to dissolve completely.
- 3Autoclave at 121°C.
- 4Cool to 45–50°C and pour plates. citeturn421530search0turn421530search6
Pack Sizes & Suggested Pricing
| 100 g | AUD 42 |
| 250 g | AUD 86 |
| 500 g | AUD 145 |
| 1 kg | AUD 248 |
| 5 kg | AUD 960 |
AuSaMicS Compliance & Supply Notes
Supplied for laboratory and research workflows. Batch-specific documentation may include Certificate of Analysis, Technical Data Sheet, and Safety Data Sheet depending on customer requirements.
For laboratory and research use only. Not for household, therapeutic, or pharmaceutical applications.