Microbiology

Prepare Liver infusion media with Thermo Scientific™ Oxoid™ Liver Desiccated Bacteriological. Liver Desiccated is prepared by the dehydration of fresh pork livers under carefully controlled conditions designed to ensure maximum retention of nutritive properties, and is equivalent to five times its weight of fresh liver.

• Dehydrated whole liver, specially manufactured for the preparation of infusion media.
• Not all products are available for sale in all territories. Please inquire.
• Remel™ and Oxoid™ products are now part of the Thermo Scientific brand.

The Oxoid Liver Digest Neutralized is a biologically standardized papaic digest of ox liver for use as a source of nutrients in microbiological culture media.

Detect salmonellae including Salmonella arizonae with the diagnostic Thermo Scientific™ Oxoid™ Lysine Iron Agar (Dehydrated). This differential medium detects salmonellae (including lactose fermenting Salmonella arizonae) by lysine decarboxylase activity and H₂S production.

Lysine Iron Agar, Oxoid Composition

Lysine Iron Agar, Oxoid Preparation:
Suspend 34g in 1 litre of distilled water. Bring to the boil to dissolve completely. Dispense into tubes and sterilise by autoclaving at 121° C for 15 minutes. Cool the tubes in an inclined position to form slants with deep butts.

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.

Isolate and enumerate wild yeasts encountered in brewing while suppressing pitching yeasts with Thermo Scientific™ Oxoid™ Lysine Medium (Dehydrated). This complex, synthetic medium is based on the original formula of Morris & Eddy which utilizes the susceptibility of pitching yeasts to lysine to differentiate it from the wild yeast.

Lysine Medium, Oxoid Composition

Lysine Medium, Oxoid Preparation:
Suspend 6.6g in 100ml distilled water containing 1.0ml Potassium lactate SR0037. Bring to the boil to dissolve completely. Agitate frequently to prevent superheating. Cool to 50°C and add 0.1ml of lactic acid 10% SR0021 to adjust to pH 4.8 ± 0.2. Dispense into Petri dishes and remove surface moisture by drying at 37°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.

• Oxoid Membrane Endo Agar LES (m Endo AgarLES) is an APHA recommended medium for the confirmation of coliforms.
• Also available Basic Fuchsin Indicator, Part No. BR0050A.

Membrane Endo Agar LES, Oxoid Composition

Membrane Endo Agar LES, Oxoid Preparation:
Suspend 45 grams in 1 litre of distilled water. Add 12ml of a 10% w/v solution of Basic Fuchsin. Heat gently with frequent agitation until the medium boils. DO NOT AUTOCLAVE. Cool to 45°C and dispense into 50-60 mm dishes in 4 ml volumes. For larger dishes use sufficient medium to give an equivalent depth (approx. 1.5 mm).
Plates should be protected from light and may be stored for up to two weeks in the refrigerator.

Storage conditions and Shelf life
Store the dehydrated medium below 25°C and use before the expiry date on the label.
Store the prepared medium in the dark and at 2-8°C.

Isolate and enumerate lactic acid bacteria from food with Thermo Scientific™ Oxoid™ MRS Broth (DeMan, Rogosa and Sharpe) (Dehydrated). This non-selective medium is designed to support profuse growth of lactic acid bacteria.

MRS Broth (DeMan, Rogosa and Sharpe), Oxoid Composition

MRS Broth (DeMan, Rogosa and Sharpe), Oxoid Preparation:
Add 52g to 1 litre of distilled water at approximately 60°C. Mix until completely dissolved. Dispense 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 at 2-8°C.

M17 Agar, Oxoid is used for the improved growth of Lactic Streptococci and their bacteriophages and the selective enumeration of Streptococcus thermophilus from yogurt.

M17 Agar, Oxoid Composition

M17 Agar, Oxoid Preparation:
Suspend 48.25g in 950ml of distilled water and bring gently to the boil. Sterilise by autoclaving at 121°C for 15 minutes. Cool to 50°C and add 50ml of sterile lactose solution (10% w/v).

Lactose solution 10% (w/v):
Dissolve 10g of Lactose Code LP0070 in 100ml of distilled water. Sterilise by autoclaving at 121°C for 15 minutes or by membrane filtration through a 0.2µm membrane.

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 lactic streptococci and their bacteriophages with Thermo Scientific™ Oxoid™ M17 Broth (Dehydrated). The use of M17 Broth in conjunction with M17 Agar is recommended by Terzaghi and Sandine for bacteriophage assays.

M17 Broth, Oxoid Composition

M17 Broth, Oxoid Preparation:
Suspend 37.25g in 950ml of distilled water and bring gently to the boil. Sterilize by autoclaving at 121°C for 15 minutes. Cool to 50°C and aseptically add 50ml of sterile lactose solution (10% w/v).

Lactose solution 10% (w/v):
Dissolve 10g of Lactose Code LP0070 in 100ml of distilled water. Sterilise by autoclaving at 121°C for 15 minutes or by membrane filtration through a 0.2mm membrane.

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.

MacConkey agar, Oxoid is used to detect, isolate and enumerate coliforms and intestinal pathogens in water, dairy products and biological specimens. This differential medium gives a number of diagnostic indications such as bile tolerance, colony morphology and chromogenesis. MacConkey Agar corresponds to the medium recommended by the World Health Organizaton, the Department of Health for the bacterial examination of water.

Composition of MacConkey Agar (Oxoid)

Preparation of MacConkey Agar (Oxoid):

Suspend 52g of MacConkey agar powder 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 of MacConkey Agar (Oxoid)
Store the dehydrated MacConkey agar powder at 10-30°C and use before the expiry date on the label.
Store the prepared MacConkey agar at 2-8°C.

Oxoid MacConkey Agar No. 2 is a modification of MacConkey Agar No. 3 with addition of Bile Salts No. 2 for detection of Enterococci.

MacConkey Agar No. 2, Oxoid Composition

MacConkey Agar, Oxoid Preparation:
Suspend 51.5g 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 plates at 2-8°C.

Detect and enumerate coliform organisms, including Escherichia coli, while isolating and detecting Salmonella and Shigella spp. in both clinical and food specimens using Thermo Scientific™ Oxoid™ MacConkey Agar No.3. A modification of the original MacConkey medium by the addition of selected bile salts, the medium gives improved differentiation of coliforms and non-lactose fermenting organisms while completely inhibiting Gram-positive cocci.

MacConkey Agar No.3, Oxoid Composition

MacConkey Agar, Oxoid Preparation:
Suspend 51.5g 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
The dehydrated medium should be stored at 10-30°C and used before the expiry date on the label.
Store the prepared medium at 2-8°C.

Identify coliforms from water and milk samples with differential Thermo Scientific™ Oxoid™ MacConkey Broth (Dehydrated). MacConkey Broth is the standard medium for the primary isolation of coliform bacteria, and has been recommended for this purpose by the Public Health Laboratory Service Water Committee and the World Health Organization. MacConkey Broth also conforms to the formulation specified by the UK Dept. of Health for milk grading.

MacConkey Broth, Oxoid Composition

MacConkey Broth, Oxoid Preparation:
To prepare single strength broth, add 40g to 1 litre of distilled water. Mix well and distribute into containers fitted with fermentation (Durham) tubes. 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.

Precautions
The neutral red indicator is carefully selected for this formulation and therefore shows no inhibitory effect. However, the more sensitive reaction of bromocresol purple in MacConkey Broth Purple (CM0505) is often preferred.

Detect coliform organisms in water and milk examination with Thermo Scientific™ Oxoid™ MacConkey Broth Purple (Dehydrated). Bromocresol purple indicator in the medium provides more sensitive and definite indications of acid production as compared to neutral red indicator and is less inhibitory to Escherichia coli. The use of bromocresol purple corresponds to the alternative formulations recommended in ‘The Bacteriological Examination of Water Supplies’ and ‘International Standard for Drinking Water’.

MacConkey Broth Purple, Oxoid Composition

MacConkey Broth Purple, Oxoid Preparation:
To prepare single strength broth add 40g to 1 litre of distilled water. Distribute into containers fitted with fermentation (Durham) tubes. 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.

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.

Oxoid Malt Extract Broth is used for the identification of yeast and molds in sterility testing.

Malt Extract Broth, Oxoid Composition

Malt Extract Broth, Oxoid Preparation:
Add 20g to 1 litre of distilled water. Mix well, distribute into final containers and sterilise by autoclaving at 115°C for 10 minutes. This liquid medium is recommended for the cultivation of moulds and yeasts, during tests for sterility, etc.

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

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.