Dehydrated culture media
TSYEA Agar (Tryptone Soy Yeast Extract Agar) ISO
For the confirmation of Listeria spp.
- Cat. No.
- LC-1398
- Category
- Dehydrated culture media
- Format
- 500 g
- Storage
- 2 to 25 °C
- Minimum guaranteed shelf life
- 15 months
- Standards
- ISO 11133ISO 11290
TSYE Agar (Tryptone Soy Yeast Extract) is a general purpose medium which supports the growth of a wide variety of microorganisms.
Key features
Applications
Confirmation of Listeria.
Industry
Food.
Standards
ISO 11133, ISO 11290.
Preparation
51 g in one liter of distilled water; boil for one minute, sterilize in autoclave at 121 °C for 15 minutes.
Principles and uses
The formula conforms to ISO 11290 and is used for the confirmation of Listeria monocytogenes colonies and to subculture suspected Listeria colonies.
Enzymatic digest of casein, yeast extract and papaic digest of soyabean meal provide nitrogen, vitamins, minerals and amino acids essential for growth. Glucose is the fermentable carbohydrate providing carbon and energy. Dipotassium hydrogen phosphate acts as a buffer system. Bacteriological agar is the solidifying agent.
Technical specifications
| Solubility | Without residues |
|---|---|
| Appearance | Fine powder |
| Color of the dehydrated medium | Beige |
| Color of the prepared medium | Amber, slightly opalescent |
| Final pH (25 °C) | 7.3 ± 0.2 |
| Amount per litre | 51 g |
| Storage | 2 to 25 °C |
Formula
| Ingredient | g/L |
|---|---|
| Enzymatic digest of casein | 17 |
| Glucose | 2.5 |
| Bacteriological agar | 15 |
| Papainic digest of soy bean | 3 |
| Sodium chloride | 5 |
| Yeast extract | 6 |
| Dipotassium hydrogen phosphate | 2.5 |
Preparation and use
Preparation
Suspend 51 grams of the medium in one liter of distilled water. Mix well and dissolve by heating with frequent agitation. Boil for one minute until complete dissolution. Sterilize in autoclave at 121 °C for 15 minutes. Cool to 45-50 °C, mix well and dispense into plates.
According to ISO 11290
Confirmation of Listeria spp. according to ISO 11290:
- Select a presumptive colony of Listeria spp.
- Streak it onto the surface of a plate of the non-selective agar TSYEA in a manner which allows the development of well-isolated colonies.
- Incubate the plates at 37 °C for 18-24 hours.
- Typical colonies of Listeria spp. are 1 to 2 mm in diameter, convex, colorless and opaque with an entire edge. When the light impacts (45°) a colony, it exhibits a blue-grey color and granular surface.
Quality control
Microbiological test
Incubation conditions: 37 °C / 24 h.
Inoculation conditions: productivity qualitative (10³-10⁴ CFU).
| Microorganism | Specification |
|---|---|
| Listeria monocytogenes 4bATCC 13932 | Good growth |
Bibliography
- ISO 11290. Horizontal method for the detection and enumeration of Listeria monocytogenes.
What you receive
The product
Shipped under controlled temperature when the product requires it.
Lot certificate
Every lot comes with its certificate.
Tracked shipment
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Frequently asked questions
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