Microbiology

Enrich and isolate Salmonella from feces and food products with Thermo Scientific™ Oxoid™ Selenite Broth Base (Lactose).The presence of Selenium in the medium provides selectivity against non-target bacteria.

Selenite Broth Base (Lactose), Oxoid Composition

Selenite Broth Base (Lactose), Oxoid Preparation:
Dissolve 4g of sodium biselenite LP0121 in 1 litre of distilled water and then add 19g of Selenite Broth Base. Warm to dissolve, mix well and fill out into containers. Sterilise in a boiling water bath, or in free flowing steam, for 10 minutes. DO NOT AUTOCLAVE.

To minimise any possible risk of teratogenicity to laboratory workers, the sodium biselenite must be added as a solution to this medium.
Robertson1 reported miscarriages and possible teratogenic effects on pregnant laboratory assistants which may have been caused by ingested sodium biselenite. Oxoid therefore removed this substance from the powdered medium.

Although no further reports have been received sodium biselenite is now considered to be very toxic and should be handled with great care.

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 away from light.

Precautions
Discard the prepared medium if large amounts of reduced selenite can be seen as a red precipitate in the bottom of the bottles.
Do not incubate longer than 24 hours because the inhibitory effect of selenite is reduced after 6-12 hours incubation.
Take sub-cultures of broth from the upper third of the broth column, which should be at least 5 cm in depth.

Nutrient agar (500g, Oxoid) is a culture media that used to cultivate and isolate fastidious pathogens and other microorganisms. This non-selective medium contains beef extracts combined with peptone, yeast extracts and sodium chloride to provide the nitrogen compounds, carbon, vitamins and some trace ingredients necessary for the growth of bacteria. A general-purpose medium which may be enriched with up to 10% blood or other biological fluid.

Nutrient Agar, Oxoid Composition

Nutrient Agar, Oxoid Preparation:

Powder: Suspend 28g of nutrient agar in 1 litre of distilled water. Bring to the boil to dissolve completely. 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 medium at 2-8°C.

Pre-enrich food samples prior to the isolation of Salmonella species using Thermo Scientific™ Oxoid™ Buffered Peptone Water (ISO) (Dehydrated). Buffered Peptone Water is a non-selective pre-enrichment medium and is tested in accordance with ISO 6579 and ISO 11133:2014. It also provides conditions for resuscitation of cells that have been injured by processes of food preservation.

Buffered Peptone Water (ISO), Oxoid Composition

Buffered Peptone Water (ISO), Oxoid Preparation:
Add 20.0g of Buffered Peptone Water (ISO) to 1 litre of distilled water. Mix well and distribute into final containers. Sterilise by autoclaving at 121°C for 15 minutes.

Method of use
The sample is added to Buffered Peptone Water (ISO) at a ratio of 1:10, and incubated at 36°C ± 2°C for 16-20 hours before transfer to selective enrichment media.

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

Thermo Scientific™ Oxoid Lactic Acid is a solution for addition to culture media, primarily to lower the pH.

• Produce suitable gaseous atmosphere for growth of microaerophilic microorganisms with the Oxoid CampyGen Compact Sachet.
• For use in Compact Plastic Pouch.
• Each pouch holds 2 standard size petri dishes.
• No water or catalyst required.
• No hydrogen gas produced.
• Use with Compact Plastic Pouch Part No. AG0020C and AnaeroGen™ Compact Sealing Clip, Part No. AN0005C.

Precautions
This product is for in vitro use only
As soon as the CampyGen paper sachet is exposed to air, the reaction will start. It is therefore essential that the paper sachet is placed in the jar and the jar sealed within one minute.
The reaction of the ascorbic acid with oxygen is exothermic. However, the temperature of the CampyGen paper sachet will not exceed 65°C.

Storage
Store at 2-25°C. Under these conditions, the CampyGen sachets will retain their reactivity until the expiry date given on the outer box and on the foil sachet.

Grow a wide variety of microorganisms with Thermo Scientific™ Oxoid™ Tryptone Soya Broth (a.k.a Tryptic Soy Broth) EP/USP/BP/JP (Dehydrated). The general purpose medium, containing two peptones, is suitable for the cultivation of both aerobes and anaerobes. It is specified in International Pharmacopoeia and food testing methods for the growth of a wide variety of organisms.

Tryptone Soya Broth, Oxoid Composition

*Contains papain

Tryptone Soya Broth, Oxoid Preparation:
Add 30g to 1 litre of water (purified as required), mix well and distribute into final containers. 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 medium away form the light at room temperature.

Enrich and recover Vibrio species from food, water, and clinical samples with Thermo Scientific™ Oxoid™ Alkaline Peptone Water. This medium is selective by exploiting the ability of Vibrio species to tolerate alkaline conditions and high sodium chloride levels. The peptone content provides the conditions for growth and recovery of Vibrio species, supplying vitamins, minerals, and nitrogen in the form of amino acids.

Alkaline Saline Peptone Water, Oxoid Composition

Alkaline Saline Peptone Water, Oxoid Preparation:

Add 30g to 1 litre of distilled water. Mix well, distribute into final containers and sterilize by autoclaving at 121°C for 15 minutes.

Storage conditions and Shelf life
The dehydrated medium should be stored at 10-30°C and used before the expiry date on the label.
Store the prepared medium may be stored for up to 1 month at room temperature.

Selectively enumerate yeasts and molds from foodstuffs with Thermo Scientific™ Oxoid™ Oxytetracycline Glucose Yeast Extract Agar Base (Dehydrated). The medium is based upon the formulation described by Mossel et al. which utilizes oxytetracycline selectivity to provide increased counts of yeasts and molds compared to other media that utilize a low pH as a selective agent. Improve the recovery of physically stressed yeast cells on this neutral pH medium.

Oxytetracycline Glucose Yeast Extract Agar Base (Dehydrated), Oxoid Composition

Oxytetracycline Glucose Yeast Extract Agar, Oxoid Preparation:
Suspend 18.5g in 500ml of distilled water and bring gently to the boil to dissolve completely. Sterilise by autoclaving at 115°C for 10 minutes. Allow the medium to cool to 50°C and aseptically add the contents of one vial of Oxytetracycline GYE Selective Supplement (SR0073) reconstituted as directed. Mix thoroughly and pour into sterile Petri dishes. The pH of this medium should be 7.0±0.2 @ 25°C.

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.

Precautions:
The lactic-acid bacteria are inhibited on this medium.

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.

Cultivate and isolate fastidious microorganisms with clearly visible hemolytic reactions with Thermo Scientific™ Oxoid™ Columbia Blood Agar Base (Dehydrated) when used with whole defibrinated blood (SR0050). Columbia Blood Agar Base is an ideal base medium for preparation of blood agar, chocolate agar and for preparation of various selective and identification media.

Columbia Blood Agar Base, Oxoid Composition

Columbia Blood Agar, Oxoid Preparation:
Add 39g to 1 litre of distilled water. Boil to dissolve the medium completely. Sterilise by autoclaving at 121°C for 15 minutes. Cool to 50°C and add 5% sterile defibrinated blood.

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 at 2-8°C.

Precautions
Brucella cultures are highly infective and must be handled under properly protected conditions. Incubate in 5-10% carbon dioxide atmosphere for 24-48 hours.
Campylobacter species are best grown at 42°C (except Campylobacter fetus subsp. fetus) in a micro-aerophilic atmosphere (Oxoid Campylobacter Gas Generating Kit BR0056 or BR0060 or CampyGen CN0025/CN0035).
Staph./Strep. supplemented plates should be incubated aerobically at 35°C for 18 hours. Incubation in carbon dioxide- enriched air will cause inhibition of staphylococcal growth.
Streptococcus Selective Supplement SR0126 supplemented plates may be incubated aerobically or anaerobically at 35°C for 18 hours.
Prepared plates of both supplemented media should be used within 18 hours of preparation for maximum selectivity. Gardnerella supplemented plates should be incubated at 35°C for 48 hours in an atmosphere containing 7% carbon dioxide.
Carry out confirmatory tests on all colonies from horse blood medium and on beta-haemolytic colonies from human or rabbit blood medium.
Incubate plates of Clostridium E-Y Agar anaerobically at 35°C for 18 hours, look for lecithinase activity (pearly layer) and for proteolysis. Lecithinase activity is inhibited in the presence of specific anti-toxin.

Identify dermatophytes and other fungi and yeasts in clinical specimens and environmental samples with the acidic Thermo Scientific™ Oxoid™ Sabouraud Dextrose Agar. The low pH supports the growth of fungi while inhibiting bacterial growth in mixed samples. Fungi maintain their typical cultural appearance and, thus, may be readily identified according to standard macroscopic characters.

Directions
Add 65g of Sabouraud Dextrose Agar to 1L of distilled water. Sterilize the medium by autoclaving at 121°C for 15 mins. Mix well and pour into a clean petri dish.

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

Oxoid Sabouraud Liquid Medium is an USP formulation for mycological sterility testing.

Sabouraud Liquid Medium, Oxoid Composition

Sabouraud Liquid Medium, Oxoid Preparation:
Dissolve 30g in 1 litre of water (purified as required). Mix well, distribute into final containers 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 medium away from light between 2-25°C.

Produce suitable gaseous atmosphere for growth of microaerophilic microorganisms with the Oxoid CampyGen 3.5L Sachet.

• No water or catalyst required
• No hydrogen gas produced
• For use with Thermo Scientific Oxoid 3.5L Anaerobic Jar, Part No. HP0011A, HP0031A

Precautions
This product is for in vitro use only
As soon as the CampyGen paper sachet is exposed to air, the reaction will start. It is therefore essential that the paper sachet is placed in the jar and the jar sealed within one minute.
The reaction of the ascorbic acid with oxygen is exothermic. However, the temperature of the CampyGen paper sachet will not exceed 65°C.

Storage
Store at 2-25°C. Under these conditions, the CampyGen sachets will retain their reactivity until the expiry date given on the outer box and on the foil sachet.

Achieve maximum recovery of microorganisms during dilution with this protective, isotonic Thermo Scientific™ Oxoid™ Maximum Recovery Diluent (Dehydrated).

Maximum Recovery Diluent combines the protective effect of peptone in the diluting solution1 with the osmotic support of physiological saline. The low peptone concentration in the diluent reduces organism multiplication in the sample for at least 45 minutes during the dilution stage.

Maximum Recovery Diluent, Oxoid Composition

Maximum Recovery Diluent, Oxoid Preparation:
Dissolve 9.5g in 1 litre of distilled water. Dispense into the final containers 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 medium at room temperature.

Presumptively detect, isolate and enumerate pathogenic staphylococci in milk, food, fish and other specimens with Thermo Scientific™ Oxoid™ Mannitol Salt Agar (Dehydrated). Due to high concentrations of salt in the medium, most unwanted bacteria are inhibited with the exception of some halophilic marine organisms. Presumptive coagulase-positive staphylococci produce colonies surrounded by bright yellow zones while non-pathogenic staphylococci produce colonies with reddish purple zones.

Mannitol Salt Agar, Oxoid Composition

Mannitol Salt Agar, Oxoid Preparation:
Suspend 111g in 1 litre of distilled water and bring to the boil to dissolve completely. 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.

Detect coliform organisms in water, waste water and dairy products with selective Thermo Scientific™ Oxoid™ Lauryl Tryptose Broth (Dehydrated), while conforming to the formula detailed by American Public Health Association. Lauryl Tryptose Broth is designed to promote a rich growth and copious gas production from small inocula of coliform organisms.

Lauryl Tryptose Broth, Oxoid Composition

Lauryl Tryptose Broth, Oxoid Preparation:
Dissolve 35.6g in 1 litre of distilled water and distribute into containers with fermentation tubes (Durham). 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 medium at room temperature.

Precautions
If stored at 2-8°C the broth will become cloudy or form a precipitate. This should clear at room temperature but gas formation is the criterion of growth not turbidity.

• Produce suitable gaseous atmosphere for growth of microaerophilic microorganisms with Oxoid CampyGen 2.5L Sachet.
• No water or catalyst required.
• No hydrogen gas produced.
• For AnaeroJar™ 2.5L, Part No. AG0025A.

Precautions
This product is for in vitro use only
As soon as the CampyGen paper sachet is exposed to air, the reaction will start. It is therefore essential that the paper sachet is placed in the jar and the jar sealed within one minute.
The reaction of the ascorbic acid with oxygen is exothermic. However, the temperature of the CampyGen paper sachet will not exceed 65°C.

Storage
Store at 2-25°C. Under these conditions, the CampyGen sachets will retain their reactivity until the expiry date given on the outer box and on the foil sachet.

Oxoid Malt Extract is recommended for use in media for yeast and mold growth. An extract of sprouted grain with conserved nitrogen and carbohydrate constituents