Microbiology

• 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.

Oxoid MLCB Agar is used for the selective isolation of Salmonella spp., not S.Typhi or S. Paratyphi A.

MLCB Agar, Oxoid Composition

MLCB Agar, Oxoid Preparation:
Suspend 49.0g in 1 litre of distilled water. Mix and bring gently to the boil with frequent agitation to dissolve the medium completely. Cool to 50°C and pour approximately 20ml into sterile Petri dishes.
DO NOT AUTOCLAVE OR OVERHEAT.

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
The identity of colonies presumed from their appearance to be Salmonella spp. must be confirmed by biochemical and serological testing. In common with other enteric media care must be taken to ensure the purity of colonies taken for further testing as organisms that are inhibited from developing into colonies remain viable and may accidentally be picked on sub-culture.

This product has been discontinued. Please contact us for more information.

Oxoid GBS Agar Base (Group B Streptococci Medium) (Islam) is used for the isolation and detection of Group B Streptococci in clinical specimens.

GBS Agar Base (Islam), Oxoid Composition

GBS Agar Base (Group B Streptococci Medium) (Islam), Oxoid Preparation:
Suspend 45.2g in 1 litre of distilled water and bring to the boil to disolve completely. Sterilise by autoclaving at 121°C for 15 minutes. Cool to 50°C and aseptically add 50ml of sterile inactivated Horse Serum. Mix well and pour into 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 plates at 2-8°C away from light.

Precautions
The medium must be at its correct pH value to ensure good pigmentation.
Some strains of Group B streptococci do not produce pigmented colonies.
Do not hold the molten medium any longer than necessary.

• Oxoid AFPA Medium Base is a selective identification medium for the detection of Aspergillus flavus and Aspergillus parasiticus.
• Also available: Membrane Clostridium Perfringens Selective Supplement, Part No. SR0188E.

AFPA Medium Base, Oxoid Composition

AFPA Medium Base, Oxoid Preparation:

Suspend 22.75g in 500ml (45.5g/l) of distilled water and heat to dissolve completely. Reconstitute one vial SR0078E per 500ml medium or one vial SR0078H per 2 litres medium, as directed. Add the vial contents to the AFPA Base. Sterilise by autoclaving at 121°C for 15 minutes. Cool to 50°C. 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 plates at 2-8°C.

Enrich and improve the isolation of salmonellae from feces and food samples with Thermo Scientific™ Oxoid™ Selenite Cystine Broth Base. This modified medium is based upon the formulation described by Leifson with added cystine.

Selenite Cystine Broth Base, Oxoid Composition

Selenite Cystine Broth, Oxoid Preparation:
Dissolve 4g of sodium biselenite LP0121 in 1 litre of distilled water and then add 19g of Selenite Cystine Broth Base. Warm to dissolve and dispense into containers. Sterilise by placing in free flowing steam for 15 minutes. DO NOT AUTOCLAVE.

Robertson reported miscarriages and possible tetragenic effects on pregnant laboratory workers which may have been caused by the ingestion of sodium biselenite. To minimise any possible risk of teratogenicity to laboratory workers the sodium biselenite is not included in the dry powder but should be prepared separately as a solution to which the Selenite Cystine Broth Base is added.

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
Observe the precautionary comments made about sodium biselenite in Selenite Broth Base CM0395.
Discard the prepared medium if large amounts of reduced selenite can be seen as a red precipitate in the bottom of the bottle.
Do not incubate longer than 24 hours because the inhibitory effect of selenite is reduced after 6-12 hours incubation.
Take subcultures of broth from the upper third of the broth column which should be at least 5 cm in depth.

• Oxoid Campylobacter Agar Base is used for the isolation of Campylobacter jejuni and Campylobacter coli from human, animal, avian and environmental specimens.
• Also available Campylobacter Selective Supplement (Blaser-Wang), Part No. SR0098E NMKL; Bolton Broth Selective Supplement, Part No. SR0183E; Modified Bolton Broth Selective Supplement, Part No. SR0208E; Modified Preston Campylobacter Selective Supplement, Part No. SR0204E; and Campylobacter Selective Supplement Preston, Part No. SR0117E.

Campylobacter Agar Base, Oxoid Composition

Preston Campylobacter Selective Agar, Oxoid Preparation:
Suspend 18.5g of Campylobacter Agar Base in 475ml of distilled water and bring to the boil to dissolve completely. Sterilise by autoclaving at 121°C for 15 minutes. Cool to 50°C. Aseptically add 25ml of Lysed Horse Blood (SR0048), and 1 vial of Preston Campylobacter Selective Supplement (SR0117 or SR0204) reconstituted as directed and one vial of Campylobacter Growth Supplement (SR0232). Mix well and pour into sterile Petri dishes.

Preston Campylobacter Selective Enrichment Broth, Oxoid Preparation:
Dissolve 12.5g of Nutrient Broth No.2 (CM0067) in 475ml of distilled water and sterilise by autoclaving at 121°C for 15 minutes. Cool to 50°C or below. Aseptically add 25ml of Lysed Horse Blood (SR0048), 1 vial of Preston Campylobacter Selective Supplement (SR0117 or SR0204) and 1 vial of Campylobacter Growth Supplement (SR0232). Aseptically dispense 5ml volumes in sterile small screw-capped bottles. The Selective Enrichment Broth may be stored for up to 7 days at 2-8°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 plates at 2-8°C.

Isolate Legionella from environmental samples and clinical specimens using Thermo Scientific™ Oxoid™ Legionella CYE Agar Base when used with Legionella Growth Supplement SR01110. Legionella CYE Agar Base is a non-selective medium that exhibits optimal recovery of legionellaceae in short incubation periods from both environmental samples and clinical specimens.

Legionella CYE Agar Base, Oxoid Composition

BCYE Agar, Oxoid Preparation:
Suspend 2.5g of Legionella CYE Agar Base per 90ml of distilled water and bring gently to the boil to dissolve completely. Sterilise by autoclaving at 121°C for 15 minutes. Reconstitute one vial SR0110A per 100ml medium or one vial SR0110C per 500ml medium, as directed. Allow medium to cool to 50°C and aseptically add the vial contents. Mix gently and pour into sterile Petri dishes. The final pH of the medium should be 6.9 ± 0.2.

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

**This product is not available at the moment. Please contact us for more information.

Oxoid Universal Beer Agar is used for the isolation of beer spoilage microorganisms.

Universal Beer Agar, Oxoid Composition

Universal Beer Agar, Oxoid Preparation:
Suspend 62g in 750ml of distilled water and bring to the boil to dissolve completely. Add 250ml beer, without degassing, to the hot medium and mix gently. Distribute into final containers and sterilise by autoclaving at 121°C for 10 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.

Precautions
When handling cycloheximide observe the precautions to be taken under HAZARDS.

• Oxoid Clostridium Difficile Agar Base is used for the isolation of Clostridium difficile.
• Also available Clostridium Difficile Selective Supplement, Part No. SR0096E.

lostridium Difficile Agar Base, Oxoid Composition

Clostridium Difficile Agar, Oxoid Preparation:
Suspend 34.5g in 500ml of distilled water and bring gently to the boil to dissolve completely. Sterilise by autoclaving at 121°C for 15 minutes. Allow to cool to 50°C and add aseptically the contents of 1 vial of Oxoid Clostridium Difficile Supplement (SR0096) reconstituted as directed, together with 7% (v/v) Defibrinated Horse Blood (SR0050). Sheep Blood (SR0051) may be used in place of Horse Blood but some strains of the organism will show a slightly reduced growth recovery. 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 medium at 2-8°C no longer than 5-7 days.

Precautions
Colonies of Clostridium difficile from faecal cultures are smaller when egg yolk is used in place of horse blood.

The Oxoid formula does not contain the neutral red indicator proposed by George et al. because it is designed for use with horse blood. On this medium the typical colour of the colony of Clostridium difficile will not appear however there will be a fluorescent reaction.

Typical Gram stain morphology of Clostridium difficile may not be evident in colonies picked from this medium because of the antibiotics present. Subculture to blood agar to obtain characteristic morphology.

The Oxoid Tryptone Bile Agar is used for the detection and enumeration of E.coli biotype 1 in foods.

Tryptone Bile Agar, Oxoid Composition

Tryptone Bile Agar, Oxoid Preparation:
Suspend 36.5g in 1 litre of distilled water and bring gently to the boil to dissolve completely. Sterilise by autoclaving at 121°C for 15 minutes. Cool to 50°C and pour 12-15ml of the medium 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 plates at 2-8°C.

Oxoid BiGGY Agar (Nickerson Medium) for the isolation and presumptive identification of Candida spp.

BiGGY Agar, Oxoid Composition

BiGGY Agar, Oxoid Preparation:
Suspend 42g in 1 litre of distilled water and bring gently to the boil to dissolve the agar. Allow to cool to 50-55°C. Mix gently to disperse the flocculant precipitate and pour into sterile Petri dishes.
DO NOT AUTOCLAVE THE MEDIUM.

Storage conditions and Shelf life
Store the dehydrated medium at 10-30°C and use before the expiry date on the label.
Medium should be freshly prepared just prior to use.

Precautions
Carry out further tests to confirm identity of isolated yeasts.
Do not use slants of medium because the reactions are unsatisfactory.
The flocculent precipitate present in the molten medium must be evenly suspended whilst dispensing the agar.

• Oxoid Perfringens OPSP Agar Base is used for the enumeration of Clostridium perfringens in foods.
• lso available Perfringens OPSP Supplement A, Part No. SR0076E and Perfringens OPSP Supplement B, Part No. SR0077E.

Perfringens OPSP Agar Base, Oxoid Composition

Perfringens OPSP Agar, Oxoid Preparation:
Suspend 22.8g in 500ml of distilled water and bring gently to the boil to dissolve completely. Sterilise by autoclaving at 121°C for 15 minutes. Allow to cool to 50°C and aseptically add the contents of one vial each of Perfringens Agar (OPSP) supplements A and B (SR0076 and SR0077) which have been rehydrated as directed. Mix well and pour into sterile 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 medium at 2-8°C.

Precautions
The production of black colonies on this medium is a presumptive identification of Clostridium perfringens. Further identification tests must be carried out.

An anaerobic enrichment broth for Staphylococcus aureus.

Giolitti-Cantoni Broth, Oxoid Composition

Giolitti-Cantoni Broth, Oxoid Preparation:
Suspend 54.2g in one litre of distilled water and heat gently to dissolve. Dispense 19ml amounts into 20 x 200mm test tubes and sterilise by autoclaving at 121°C for 15 minutes. Cool rapidly then aseptically add to each tube 0.3ml of a sterile solution of Potassium tellurite 3.5% SR0030.
The medium requires the addition of a 3.5% solution of Potassium tellurite when there is a direct addition of 1g of the sample to 19mls of broth. This level of Potassium tellurite is necessary to suppress the high numbers of contaminating organisms that could be expected.
The use of a diluted solution of Potassium tellurite is applicable when a 1 in 10 dilution of the food sample is carried out. In such cases the SR0030 should first be diluted 1 in 10 with sterile distilled water.
The addition of 0.1% Tween 80 can be recommended in order to improve recovery of heat injured Staphylococcus aureus cells e.g. from milk powder. 1g of Tween 80 should be added to 1 litre of CM0523 prior to autoclaving.

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.

• Oxoid MacConkey Agar w/o Salt (Dehydrated) is a differential medium on which swarming of Proteus species is suppressed.
• For urine examination.

MacConkey Agar without Salt (Dehydrated), Oxoid Composition

MacConkey Agar, Oxoid Preparation:
Suspend 47g in 1 litre of distilled water. Bring to the boil to dissolve completely. Sterilise by autoclaving at 121°C for 15 minutes. Mix well before pouring. Dry the surface of the gel before inoculation.

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
The colonial characteristics described give presumptive identification only of the isolated organisms. It is necessary to subculture and carry out confirmation tests for final identification.
To enhance the pigment of suspected Staphylococcus aureus, hold the plates on the bench at ambient temperature for 12-18 hours.
This medium may produce a discrete precipitate on cold storage of 2 – 10°C. This in no way affects the performance of the medium.

Oxoid Tinsdale Agar Base is used for the isolation and identification of Corynebacterium diphtheriae.

Tinsdale Agar Base, Oxoid Composition

Tinsdale Agar, Oxoid Preparation:
Suspend 9g of agar base in 200ml of distilled water. Bring to the boil and dissolve completely. DO NOT AUTOCLAVE. Allow to cool to approximately 50°C and add the contents of one vial of Oxoid Tinsdale Supplement SR0065 reconstiuted as directed. Mix throughly 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 medium at 2-8°C for not more than 4 days.

Precautions
Further tests must be carried out on colonies suspected as Corynebacterium diphtheriae, including cell morphology after sub-culture to Loeffler’s Medium and examination for toxin production.
Do not incubate Tinsdale’s Agar plates in enhanced CO2 atmosphere (5-10% v/v).

Thermo Scientific™ Oxoid Iso-Sensitest Agar is a semi-defined medium designed for antimicrobial susceptibility testing.

Iso-Sensitest Agar, Oxoid Composition

Iso-Sensitest Agar, Oxoid Preparation:
Suspend 31.4g in 1 litre of distilled water and bring to the boil to dissolve the agar. 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 and use as freshly as possible.

Isolate Salmonella and Shigella from clinical specimens and foods with selective Thermo Scientific™ Oxoid™ XLD Agar (Dehydrated). The medium relies on xylose fermentation, lysine decarboxylation and production of hydrogen sulphide for the primary differentiation of shigellae and salmonellae from non-pathogenic bacteria. The careful addition of sodium desoxycholate inhibits the growth of coliforms without decreasing the ability to support shigellae and salmonellae.

XLD Agar (Dehydrated), Oxoid Composition

XLD Agar (Dehydrated), Oxoid Preparation:
Suspend 53g in 1 litre of distilled water. Heat with frequent agitation until the medium boils. DO NOT OVERHEAT. Transfer immediately to a water bath at 50°C. Pour into sterile Petri dishes as soon as the medium has cooled.

It is important to avoid preparing large volumes which will cause prolonged heating.

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.

A medium specially designed to give large, clear zones with all antibiotics, without the addition of lysed or whole blood.

Sensitest Agar, Oxoid Composition

Sensitest Agar, Oxoid Preparation:
Suspend 32g in 1 litre of distilled water and bring to the boil to dissolve the agar. 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 of agar at 2-8°C.

Precautions
As with other susceptibility testing media, Sensitest Agar should be used for rapidly growing aerobic organisms only. It should not be modified by the addition of carbohydrates or incubated in a CO2 enriched atmosphere.
If the medium is used for Bell’s CDS method then the specified discs and technique must be used. Refer to the monograph cited in the References.

DCLS Agar is a modified form of Desoxycholate Citrate Agar which includes sucrose in its formulation. The addition of this fermentable carbohydrate increases the usefulness of the medium because non-pathogenic sucrose-fermenting organisms may be recognised by their red colonies, e.g. some Proteus, Enterobacter and Klebsiella species.

DCLS Agar, Oxoid Composition

DCLS Agar, Oxoid Preparation:
Suspend 50g in 1 litre of distilled water. Bring to the boil to dissolve the medium. Cool to 50°C and pour into sterile Petri dishes.
DO NOT AUTOCLAVE.

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.

Precautions
Boil the medium for the minimal period of time to get the agar into solution. Overheating reduces the agar gel strength and increases the degree of inhibition. It is therefore important not to hold the molten medium at 50°C for more than the short time required to distribute it into dishes.

Selectively isolate Neisseria species with Thermo Scientific™ Oxoid™ GC Agar Base (Dehydrated). GC Agar Base has been formulated to include Special Peptone LP0072 which is a mixture of meat and plant enzymatic digests. The presence of starch in the medium ensures that toxic metabolites produced by Neisseria are absorbed. Phosphate buffers are included to prevent changes in pH due to amine production that would affect the survival of the organism

GC Agar Base, Oxoid Composition

Diagnostic Sensitivity Test Agar was developed in Oxoid as a dual purpose medium which would satisfy both diagnostic and susceptibility requirements.

Diagnostic Sensitivity Test Agar, Oxoid Composition

Diagnostic Sensitivity Test Agar, Oxoid Preparation:
Add 40 g to 1 litre of distilled water. Bring to the boil to dissolve completely. Sterilise by autoclaving at 121°C for 15 minutes.
For blood agar, cool the base to 50°C and add 7% of Defibrinated Horse Blood SR0050. Mix with gentle rotation and pour into Petri dishes (12 ml for a 9 cm dish) or other containers.
RECONSTITUTION AND MIXING SHOULD BE PERFORMED IN A FLASK AT LEAST 2.5 TIMES THE VOLUME OF MEDIUM TO ENSURE ADEQUATE AERATION OF THE 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 agar plates at 2-8°C.

Precautions
Diagnostic Sensitivity Test Agar has reduced thymidine activity and this will affect its performance as a primary isolation medium.

Oxoid Azide Blood Agar Base is a selective media for the detection and isolation of streptococci and staphylococci from feces, sewage and other specimens.

Azide Blood Agar Base, Oxoid Composition

Azide Blood Agar Base Oxoid Preparation:
Suspend 30g in 1 litre of distilled water and bring to the boil to dissolve completely. Sterilise by autoclaving at 121°C for 15 minutes. For azide blood agar, cool to 45-50°C and add 5% of sterile blood.

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

Precautions
Proteus and Escherichia species may not always be inhibited on the Edward’s formulation.
Always use a light inoculum for best selective results.
Anaerobic incubation will enhance haemolytic reactions.
Haemolytic reactions will not be typical on Packer’s modification of Azide Blood Agar Base. Streptococcus lactis will not grow on Packer’s modification with 5% sheep blood.
Read the section on Hazard Precautions for azide-containing media.

Wort Agar is a general purpose mycological medium, equivalent to the medium described by Parfitt and especially suitable for the cultivation and enumeration of yeasts. The medium which duplicates the composition of natural wort, is of an acidity which is optimal for many yeasts but inhibitory to most bacteria. Parfitt investigated the relative merits of wort agar and other media for the count of yeasts and moulds in butter, and recommended the use of dehydrated whey, malt or wort agar for the purpose. Scarr employed a modified wort agar (’osmophilic agar’) for the examination of sugar products for osmophilic yeasts. Scarr’s technique is also used for the determination of osmophilic yeasts occurring in materials used in the manufacture of soft drinks.

Wort Agar, Oxoid Composition

Wort Agar, Oxoid Preparation:
Suspend 50g in 1 litre of distilled water and bring to the boil to dissolve completely. Sterilise by autoclaving at 121°C for 15 minutes.
PROLONGED OR EXCESSIVE HEATING WILL DIMINISH THE GEL STRENGTH OF THE 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.

Precautions
Do not remelt the solid agar, it will destroy the gel. The surface of the agar is soft but suitable for poured inocula.