Dehydrated culture media
Tryptose Blood Agar Base
Highly nutritious medium especially developed to prepare blood agar which enhances the development of fastidious organisms.
- Cat. No.
- LC-1162
- Category
- Dehydrated culture media
- Format
- 500 g
- Storage
- 2 to 25 °C
- Minimum guaranteed shelf life
- 15 months
Tryptose Blood Agar Base is used with blood in isolating, cultivating and determining the hemolytic reactions of fastidious microorganisms. The agar base medium with tryptose has no dextrose because dextrose interferes with hemolytic reactions. Tryptose Blood Agar Base with added blood gives good haemolytic reactions and without blood it will sustain good to excellent growth of many demanding organisms. Tryptose Blood Agar Base is a nutritious infusion-free basal medium typically supplemented with 5-10% sheep, rabbit or horse blood for use in isolating, cultivating and determining hemolytic reactions of fastidious pathogenic microorganisms.
Key features
Applications
Enrichment of fastidious microorganisms.
Industry
General cultivation.
Preparation
30 g in one liter of distilled water; boil for one minute, sterilize in autoclave at 121 °C for 15 minutes; for blood agar add 7% of sterile blood.
Principles and uses
Tryptose is the source of nitrogen, carbon and amino acids in Tryptose Blood Agar Base. Beef extract provides additional nitrogen. Sodium chloride maintains osmotic balance. Agar is the solidifying agent. Supplementation with 5-10% blood provides additional growth factors for fastidious microorganisms and is used to determine hemolytic patterns of bacteria.
Technical specifications
| Solubility | Without residues |
|---|---|
| Appearance | Fine powder |
| Color of the dehydrated medium | Beige |
| Color of the prepared medium | With blood: opaque cherry red |
| Final pH (25 °C) | 7.2 ± 0.2 |
| Amount per litre | 30 g |
| Storage | 2 to 25 °C |
Formula
| Ingredient | g/L |
|---|---|
| Bacteriological agar | 12 |
| Beef extract | 3 |
| Sodium chloride | 5 |
| Tryptose | 10 |
Preparation and use
Preparation
Suspend 30 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. To prepare the blood agar, cool to 45-50 °C and add 7% of sterile blood. Mix well, avoiding bubble formation, and dispense into plates.
Instructions for use
Use standard procedures to obtain isolated colonies from specimens. Incubate at 35 ± 2 °C for 24-48 hours.
Results:
- Alpha-hemolysis: greenish discoloration of medium.
- Beta-hemolysis: clear zone surrounding colony.
- Gamma-hemolysis: no change.
Quality control
Microbiological test
Incubation conditions: 35 ± 2 °C / 24-48 h.
| Microorganism | Specification | Characteristic reaction |
|---|---|---|
| Staphylococcus epidermidisATCC 12228 | Good growth | Hemolysis: gamma |
| Neisseria meningitidisATCC 13090 | Good growth | Hemolysis (-) |
| Streptococcus pyogenesATCC 19615 | Good growth | Hemolysis: beta |
| Staphylococcus aureusATCC 25923 | Good growth | Hemolysis: beta/gamma |
| Streptococcus pneumoniaeATCC 6305 | Good growth | Hemolysis: alpha |
Bibliography
- J. Bact., 43:33, 1942.
- Am. J. Clin. Path., 17:281, 1947.
- Snavely and Brahier. A. J. Clin. Path. 33:511, 1960.
- Hosty, Freeman and Irwin, Public Health Lab., 1953.
What you receive
The product
Shipped under controlled temperature when the product requires it.
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