Microbiology

Buffered Peptone Water (Dehydrated), CM0509B (Oxoid) is a non-selective pre-enrichment medium that used to pre-enrich food samples prior to the isolation of Salmonella species. It also provides conditions for the resuscitation of cells that have been injured by processes of food preservation.

Buffered Peptone Water, Oxoid Composition

Buffered Peptone Water, Oxoid Preparation:
Add 20g to 1 litre of distilled water. Mix well and distribute into final containers. Sterilise by autoclaving at 121°C for 15 minutes. It is extremely important that the distilled water used is of a high quality with a low mineral content/conductivity.

Storage conditions and Shelf life
Store dehydrated medium at 10-30°C and use before the expiry date of the label.
Store the prepared medium at room temperature.

Oxoid Lactose Bacteriological is a sugar suitable for inclusion in bacteriological culture media.

Phosphate Buffered Saline Tablets, Dulbecco A (PBS, Oxoid) is used for the preparation of a balanced salt solution without calcium and magnesium. PBS is normally used to rinse the cells free from growth medium before application of the chelating agent, such as Versene (diamino-ethane-tetra-acetic acid).

Content of Phosphate Buffered Saline, Oxoid:

Preparation of PBS Buffer from PBS tablets, Oxoid
Dissolve ONE tablet in 100ml of distilled water. Sterilize the PBS solution with autoclaving for 115°C for 15 mins. The tablets should be dissolving completely and free from insoluble matter.

Thermo Scientific™ Oxoid ONE Broth Salmonella Selective Supplement is a selective supplement for use with ONE Broth-Salmonella Base.

ONE Broth Salmonella Selective Supplement, Oxoid Composition

ONE Broth Salmonella Selective Medium Preparation:
Suspend 5.6g of ONE Broth-Salmonella Base in 225ml of distilled water. Sterilize by autoclaving at 121°C for 15 minutes. Cool to below 50°C and add the contents of 1 vial of ONE Broth-Salmonella Supplement (SR0242), resuspended as directed.

Storage conditions and Shelf life
The ONE Broth-Salmonella Selective Supplement should be stored in the dark at 2-8ºC. When stored as directed, the unopened products will remain stable until the expiry date printed on the packaging.

Once prepared, ONE Broth-Salmonella can be stored for up to 2 weeks when made from CM1091 and SR0242 according to the manufacturer’s instructions and stored at 2-8ºC, in the dark. A longer shelf life may be attainable, but should be validated under the relevant, local manufacturing and storage conditions.

Thermo Scientific™ Oxoid™ ONE Broth-Salmonella Supplement is for the selective enrichment of Salmonella spp. from food samples in 24 hours in a single enrichment step.

• Add to ONE Broth-Salmonella Part No. CM1091B
• Each vial supplements 500mL of medium

ONE Broth Salmonella Selective Supplement, Oxoid Composition

ONE Broth Salmonella Selective Medium Preparation:
Suspend 5.6g of ONE Broth-Salmonella Base in 225ml of distilled water. Sterilize by autoclaving at 121°C for 15 minutes. Cool to below 50°C and add the contents of 1 vial of ONE Broth-Salmonella Supplement (SR0242), resuspended as directed.

Storage conditions and Shelf life
The ONE Broth-Salmonella Selective Supplement should be stored in the dark at 2-8ºC. When stored as directed, the unopened products will remain stable until the expiry date printed on the packaging.

Once prepared, ONE Broth-Salmonella can be stored for up to 2 weeks when made from CM1091 and SR0242 according to the manufacturer’s instructions and stored at 2-8ºC, in the dark. A longer shelf life may be attainable, but should be validated under the relevant, local manufacturing and storage conditions.

A stabilised emulsion of egg yolk for use in culture media. It may be added directly to nutrient media for the identification of Clostridium, Bacillus and Staphylococcus species by their lipase activity.

Egg Yolk Emulsion, Oxoid Directions:
Suspend 21.5g of MYP Agar (CM0929) in 450ml of distilled water and bring gently to the boil to
dissolve. Sterilize by autoclaving at 121°C for 15 minutes. Cool to approximately 50°C and
aseptically add 50ml of Egg Yolk Emulsion (SR0047C) and the contents of one vial of Polymyxin B
Supplement (SR0099E) reconstituted as directed. Mix well and pour into sterile Petri dishes.
Alternatively, suspend 8g of Blood Agar Base (CM0055) in 200ml of distilled water and add 2g of
sodium chloride. Sterilize by autoclaving at 121°C for 15 minutes. Cool to approximately 50°C and
aseptically add 20ml Egg Yolk Emulsion (SR0047C). Mix well and pour into sterile Petri dishes.

Storage conditions and Shelf life
Keep at temperatures between 2° and 8 °C. Use before expiry date on the label.

Precautions
On this medium Bacillus cereus is indistinguishable from Bacillus thuringiensis.
Identify Bacillus cereus by colony form, colour, egg yolk hydrolysis and confirm with cell and spore morphology.
Occasional strains of Bacillus cereus show weak or negative egg yolk reactions.

Oxoid Dextrose Bacteriological is a sugar suitable for inclusion in bacteriological culture media.

Oxoid Sodium Chloride Bacteriological is a dehydrated salt suitable for inclusion in bacteriological culture media.

Thermo Scientific™ Oxoid Egg Yolk Tellurite Emulsion is an emulsion of egg yolk containing potassium tellurite for use in Baird-Parker Medium CM0275 and Baird-Parker Medium (ISO) CM1127.

• Oxoid Cycloheximide Solution (0.1%) (100mg/vial) is used for the suppression of fungi.
• Add to Bacillus Cereus Selective Agar Base, Part No. CM0617B; Raka-Ray Agar Base, Part No. CM0777B; and Universal Beer Agar, Part No. CM0651B.