Dehydrated culture media
Neutralizing Agar
For the detection and enumeration of microorganisms on surfaces.
- Cat. No.
- LC-1449
- Category
- Dehydrated culture media
- Format
- 500 g
- Storage
- 2 to 25 °C
- Minimum guaranteed shelf life
- 15 months
Neutralizing Agar is used to cultivate a broad range of microorganisms while neutralizing disinfectants and antimicrobials which have inherent bacteriostatic properties.
Key features
Applications
Detection and non-selective enumeration (general use).
Industry
Environmental monitoring.
Preparation
54 g in one liter of distilled water; boil for one minute, sterilize in autoclave at 121 °C for 15 minutes.
Principles and uses
Peptone provides nitrogen, vitamins, minerals and amino acids essential for growth. Yeast extract is a source of vitamins, particularly of the B-group. Dextrose is the fermentable carbohydrate providing carbon and energy. Five neutralizers inactivate a number of disinfectant and antiseptic chemicals. Sodium bisulfite neutralizes aldehydes. Sodium thioglycollate neutralizes mercurials. Sodium thiosulfate neutralizes iodine and chlorine. Lecithin neutralizes quaternary ammonium compounds. Polysorbate 80, a non-ionic surface active agent, neutralizes substituted phenolics. Bromocresol purple is used as an indicator for dextrose utilization. The organisms that ferment dextrose will turn the medium from a purple to yellow color.
Technical specifications
| Solubility | Without residues |
|---|---|
| Appearance | Fine powder |
| Color of the dehydrated medium | Green-blue |
| Color of the prepared medium | Violet |
| Final pH (25 °C) | 7.6 ± 0.2 |
| Amount per litre | 54 g |
| Storage | 2 to 25 °C |
Formula
| Ingredient | g/L |
|---|---|
| Dextrose | 10 |
| Bacteriological agar | 15 |
| Bromocresol purple | 0.02 |
| Casein peptone | 5 |
| Lecithin | 7 |
| Polysorbate 80 | 5 |
| Sodium bisulfite | 2.5 |
| Sodium thioglycollate | 1 |
| Sodium thiosulfate | 6 |
| Yeast extract | 2.5 |
Typical formula in g/L, adjusted and/or supplemented as required to meet performance criteria.
Preparation and use
Preparation
Suspend 54 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.
Instructions for use
Inoculate and incubate at 35 ± 2 °C and observe after 18-24 hours.
Quality control
Microbiological test
Incubation conditions: 35 ± 2 °C / 18-24 h.
| Microorganism | Specification |
|---|---|
| Salmonella typhimuriumATCC 14028 | Good growth |
| Escherichia coliATCC 25922 | Good growth |
| Staphylococcus aureusATCC 25923 | Good growth |
| Pseudomonas aeruginosaATCC 27853 | Good growth |
| Bacillus subtilisATCC 6633 | Good growth |
Bibliography
- Downes and Ito (ed.), 2001. Compendium of methods for the microbiological examination of foods, 4th ed. American Public Health Association, Washington, D.C.
- Association for the Advancement of Medical Instrumentation. 1984. Process control guidelines for gamma radiation sterilization of medical devices. AAMI, Arlington, VA.
What you receive
The product
Shipped under controlled temperature when the product requires it.
Lot certificate
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Tracked shipment
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