Microbiology

Selectively enrich Listeria monocytogenes and other Listeria spp. from food and environmental samples with Thermo Scientific™ Oxoid™ 24 Listeria Enrichment Broth (24 LEB) (Dehydrated). The medium provides optimal growing conditions for all Listeria species for PCR applications. It is specifically designed for use with PCR systems, such as Thermo Scientific™ SureTect™ molecular assays for Listeria.

24 LISTERIA ENRICHMENT BROTH (24 LEB), Oxoid Composition

24 LISTERIA ENRICHMENT BROTH (24 LEB), Oxoid Preparation:

Completely dissolve 21.75g of 24 LEB Base per 500ml of distilled water. Sterilize by autoclaving at 121°C for 15 minutes. Cool to 50°C. Aseptically add the contents of 1 vial of 24 LEB Selective Supplement per 500ml medium, reconstituted as directed. Cool to room temperature before use, and, once made, store the medium at 2-8°C in the dark.

Thermo Scientific™ Oxoid Standard Plate Count Agar (Plate Count Agar) is a standard medium corresponding to the APHA formulation used for milk, food and dairy products.

Standard Plate Count Agar (Plate Count Agar), Oxoid Composition

Standard Plate Count Agar (Plate Count Agar), Oxoid Preparation:
Suspend 23.5g in 1 litre of distilled water. Bring to the boil to dissolve completely. Dispense into bottles and sterilise by autoclaving at 121°C for 15 minutes.

Storage conditions and Shelf life
Store the dehydrated medium at 10-30°C and use before the expiry date on the label.
Store the prepared plates at 2-8°C.

• Oxoid Membrane Clostridium Perfringens Agar Base (m-CP Agar Base) is a chromogenic medium for rapid isolation and presumptive identification of Clostridium perfringens from water samples.
• Also available: Membrane Clostridium Perfringens Selective Supplement, Part No. SR0188E.

Membrane Clostridium Perfringens (M-CP) Agar Base, Oxoid Composition

(M-CP) Agar Base, Oxoid Preparation:

Suspend 35.55g of m-CP Agar Base in 500ml of distilled water Mix well and sterilise by autoclaving at 121°C for 15 minutes. Cool to 50°C and aseptically add the contents of one vial of m-CP Selective Supplement reconstituted as directed. Aseptically add the following sterile solutions dissolved in distilled water:

Storage conditions and Shelf life
Store the dehydrated medium at 10-30°C and use before the expiry date on the label.
Prepared medium may be stored for up to 5 days at 2-8°C in the dark.

Isolate and enumerate yeasts and molds from dairy and food products and prepare Aspergillus niger for the Harmonised Microbial Limit Tests from international pharmacopoeia with Thermo Scientific™ Oxoid™ Potato Dextrose Agar (Dehydrated). This medium is suitable for the detection and enumeration of heat resistant molds in thermally processed fruits and fruit products.

Pigment production is a critical part of the identification of the fungus. The agar used in the medium is carefully screened to ensure correct pigment production by fungi such as Fusaria spp.

Composition of Potato Dextrose Agar

Preparation of Potato Dextrose Agar, Oxoid
Suspend 39g in 1 litre of purified water and heat up to dissolve completely. Sterilise by autoclaving at 121°C for 15 minutes. Ensure the solution is well mixed before pouring.

To suppress the growth of bacteria, you can acidify the medium to pH 3.5 by adding 1 ml of lactic acid 10% SR0021 to each sterilized medium at 50°C. Note that the medium must not be heated after the addition of acid as it will destroy the gelling properties and results in hydrolysis of agar.

Storage Conditions and Shelf Life
Store the dehydrated medium at 10-30°C and use before the expiry date on the label.
Store the prepared medium at 2-8°C.

Thermo Scientific™ Oxoid Potato Dextrose Broth is a general broth for yeasts and molds.

Oxoid MRS Agar (de Man, Rogosa, Sharpe) (Dehydrated) is used for the growth of Lactobacilli.

Composition of MRS Agar, Oxoid

Preparation of MRS Agar, Oxoid

Suspend 62g of your MRS Agar in 1 litre of distilled water. You can boil to dissolve the powder completely. After a dissolve, you can sterilise the medium by autoclaving at 121°C for 15 minutes.

Storage Conditions and Shelf Life of MRS Agar, Oxoid

You can store your dehydrated MRS Agar at 10-30°C and use before the expiry date on the label. You can store the prepared plates at 2-8°C.

Oxoid Membrane Clostridium Perfringens Selective Supplement (m-CP) is a chromogenic medium for rapid and presumptive identification of Clostridium perfringens from water samples.

• Add to Membrane Clostridium Perfringens (m-CP) Agar Base, Part No. CM0992B
• Each vial of SR0188E supplements 500mL of medium

1M-Cp Selective Supplement, Oxoid Composition

1M-Cp Selective Supplement, Oxoid Preparation:

Suspend 35.55g of m-CP Agar Base in 500ml of distilled water Mix well and sterilise by autoclaving at 121°C for 15 minutes. Cool to 50°C and aseptically add the contents of one vial of m-CP Selective Supplement reconstituted as directed. Aseptically add the following sterile solutions dissolved in distilled water:

Storage conditions and Shelf life
m-CP Selective Supplement SR0188 should be stored at 2-8°C.
Store the prepared medium at 2-8°C.

Oxoid Brucella Selective Supplement is used for the isolation of Brucella spp.

• Add to Blood Agar Base No. 2, Part No. CM0271B; Columbia Blood Agar Base, Part No. CM0331B; or Brucella Medium Base, Part No. CM0169B
• Each vial supplements 500mL of medium

 Brucella Selective Supplement, Oxoid Composition

 Brucella Medium, Oxoid Preparation:
Reconstitute supplement as directed. Incubate for 10-15 minutes at 35°C. Mix thoroughly and immediately add the vial contents to 500 ml of sterile Oxoid Brucella Medium Base, cooled to 50°C together with 5-10% v/v sterile inactivated horse serum SR0035 and 1-5% w/v of a filter-sterilised 10% solution of dextrose. Mix well and pour into sterile petri dishes.

Storage conditions and Shelf life
Store the dehydrated medium at 10-30°C and use before the expiry date on the label.
Store the prepared agar plates at 2-8°C.

Agar Bacteriological (Agar No. 1, Oxoid) is a clear purified high gel strength bacteriological agar compatible with all culture media. This agar has low calcium (Ca) and magnesium (Mg) levels and has very high working gel strength (1.5% w/v).

Agar Bacteriological, Oxoid is compatible with all culture media. It can be formulated to either broth or agar of the same medium with very similar metal values. This characteristic is especially valuable in antimicrobial MIC studies where differences in mineral/metal content can profoundly influence the results. Due to the low mineral/metal content in Agar Bacteriological, Oxoid, it allows free diffusion of antimicrobial substances. As a result, it is a highly satisfactory agar for antimicrobial diffusion studies (disc diffusion susceptibility tests).

• Oxoid Aeromonas Medium Base (Ryan) is a selective differential medium for the isolation of Aeromonas hydrophila.
• Also available Ampicillin Selective Supplement, Part No. SR0136E.

Aeromonas Medium Base (Ryan), Oxoid Composition

Aeromonas Medium Base (Ryan), Oxoid Preparation:
Suspend 29.5g in 500ml of distilled water. Bring gently to the boil. DO NOT AUTOCLAVE. Cool to 50°C and aseptically add one vial of Ampicillin Selective Supplement SR0136 reconsituted as directed. Mix well and pour plates.

Storage conditions and Shelf life
Store the dehydrated medium at 10-30°C and use before the expiry date on the label.
Store the prepared plates of medium 2-8°C.

Precautions
Although Aeromonas and Plesiomonas spp will grow on the medium if ampicillin is omitted, it will be more difficult to distinguish them from the other organisms present on the plate. Suspected colonies of Aeromonas spp must be confirmed by biochemical tests.

Perform effortless Antimicrobial Susceptibility Testing (AST) using Thermo Scientific™ Oxoid™ Mueller Hinton Agar (Dehydrated), a medium designed and manufactured according to the European standard, EUCAST and the American standard, CLSI.

Composition of Mueller Hinton Agar, Oxoid

Preparation of Mueller Hinton Agar, Oxoid
Add 38g of Mueller Hinton Agar to 1 litre of distilled water. Bring to the boil to dissolve the medium completely. Sterilize by autoclaving at 121°C for 15 minutes.

Storage conditions and Shelf life:
Store the dehydrated Mueller Hinton Agar, Oxoid at 10-30°C and use before the expiry date on the label.
Store the prepared Mueller Hinton Agar plates at 2-8°C.

Precautions
Incubation in a carbon dioxide enriched atmosphere is not recommended because of its pH effect on the medium. If it is imperative to use CO₂ then known control organisms should be included with the test plates to measure its effect.
Carbohydrates should not be added to Mueller-Hinton Agar because they may influence the rate of growth of the organism and the resulting pH of the medium.
The addition of lysed horse blood to the medium may further reduce the levels of thymidine and prevent the growth of thymidine-dependent organisms.

The medium may not support the growth of some fastidious strains for example microorganisms that require thymine and thymidine for growth. Close adherence to the methodology is required to obtain satisfactory results.

For the preparation of serum-dextrose-antibiotic medium for the cultivation and isolation of Brucella using Brucella Selective Supplement SR0083 or SR0209. Without antibiotics, it may be used in conjunction with the Cruickshank dyestrip method for differentiation between strains.

Brucella Medium Base, Oxoid Composition

Brucella Medium, Oxoid Preparation:
Suspend 45 g in 1 litre of distilled water. Bring to the boil to dissolve completely. Sterilise by autoclaving at 121°C for 15 minutes. Cool to 50°C and add 5% of inactivated Horse Serum (i.e. Horse Serum held at 56°C for 30 minutes). Mix well before pouring.

Storage conditions and Shelf life
Store the dehydrated medium at 10-30°C and use before the expiry date on the label.
Store the prepared agar plates at 2-8°C.

Detect, isolate and enumerate yeasts and molds with Thermo Scientific™ Oxoid™ Malt Extract Agar (Dehydrated). Mycological peptone in the medium gives a luxuriant growth of yeasts and molds with typical morphology and pigmentation.

Malt Extract Agar, Oxoid Composition

Malt Extract Agar, Oxoid Preparation:
Suspend 50g in 1 litre of distilled water and boil to dissolve. Sterilise by autoclaving at 115°C for 10 minutes.

If it is desired to adjust the medium to pH 3.5, cool to 55°C and add approximately 2-3ml of 10% Lactic Acid SR0021 to 100ml Malt Extract Agar. Once acidified with lactic acid, the medium should not be re-heated.

Storage conditions and Shelf life
Store the dehydrated medium at 10-30°C and use before the expiry date on the label.
Store the prepared medium at 2-8°C.