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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.

Thioglycollate Medium USP – Alternative, is intended for sterility testing with certain biological products that are turbid or otherwise do not lend themselves readily to culturing in Thioglycollate Medium USP (CM0173) because of its viscosity.

Thioglycollate Medium USP – Alternative, Oxoid Composition

Thioglycollate Medium USP – Alternative, Oxoid Preparation:
Suspend 29g in 1 litre of distilled water. Bring to the boil and dissolve the medium completely. Distribute into tubes or bottles and sterilise by autoclaving at 121°C for 15 minutes.
PREPARE FRESHLY OR BOIL AND COOL THE MEDIUM JUST BEFORE USE.

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

Whilst storage of the prepared medium is not recommended, autoclaved volumes of Thioglycollate Medium USP – Alternative, should be held at 20-30°C in the dark. Storage at lower temperatures increases oxygen absorption.

Precautions
This medium lacks agar and reducing indicator, therefore it is essential that the medium is freshly prepared and used within four hours of preparation.
Thioglycollate media should not be reheated more than once because toxic oxygen radicles are formed on reheating.

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.

Detect and enumerate enterococci from water and food samples with Thermo Scientific™ Slanetz and Bartley Medium (Dehydrated). Slanetz and Bartley originally devised this medium to detect and enumerate enterococci by the technique of membrane filtration, but it has also proved useful as a direct plating medium. The medium is very selective for enterococci and, when it is incubated at elevated temperatures (44-45°C), all red or maroon colonies may be accepted as presumptive enterococci.

Slanetz and Bartley Medium (Dehydrated), Oxoid Composition

Slanetz and Bartley Medium Preparation:
Suspend 42g in 1 litre of distilled water and bring to the boil to dissolve the agar completely.

EXCESSIVE HEATING MUST BE AVOIDED. Dispense into Petri dishes and allow to solidify. It should not be remelted. The medium may be used with membrane filters or by spreading dilutions of the sample over the surface of the agar with a glass rod.

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
Count all red, maroon or pink colonies as presumptive enterococci. Not all species reduce TTC therefore pale colonies should not be ignored.
Although incubation at 35°C yields a higher count, it allows the growth of organisms which do not conform to the definition of enterococci. Incubation at 44-45°C has a selective effect and produces fewer false-positives. However, the preliminary incubation at 35°C encourages the recovery of stressed organisms.
Although the selective properties of this medium are very good it is advisable to regard the colony count as a presumptive or unconfirmed count. Further identification may be required depending on the scope of the examination.

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

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.

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.

Oxoid Muller-Kauffmann Tetrathionate Broth Base is selective enrichment medium for isolation of Salmonella spp. and suppression of Proteus species.

Muller-Kauffmann Tetrathionate Broth Base, Oxoid Composition

Muller-Kauffmann Tetrathionate Broth, Oxoid Preparation:
Suspend 82g in 1 litre of distilled water and bring to the boil. Cool below 45°C and add, just prior to use, 19ml of iodine solution and 9.5ml of a 0.1% brilliant green solution. Mix well and fill out into sterile tubes or flasks.

Dissolve the potassium iodide in approximately 5ml of distilled water, add the iodide and gently warm the solution to completely dissolve it. Make up the volume to 100ml with distilled water.

Add the brilliant green to the distilled water and shake to dissolve the dye. Heat the solution to 100°C for 30 minutes and shake from time to time whilst cooling, to ensure that the dye has completely dissolved. Store in a brown glass bottle or away from light.

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 autoclave the base broth.
Add the iodine solution and brilliant green just prior to use.
The medium is not suitable for the growth of Salmonella typhi, Salmonella sendai, Salmonella pullorum and Salmonella gallinarum.

Selectively isolate pathogenic Vibrio species with Thermo Scientific™ Oxoid™ TCBS (Thiosulfate Citrate Bile Salts Sucrose) Cholera Medium (Dehydrated). The medium has shown to be the most satisfactory and reproducible formula regardless of the complex composition. Unlike Lauryl Sulphate Tellurite Agar it does not require further additives or aseptic additions of blood. It also possesses superior growth characteristics for Vibrio species, compared with tellurite media. While inhibiting non-vibrios, it promotes rapid growth of pathogenic vibrios after overnight incubation at 35°C.

TCBS (Thiosulfate Citrate Bile Salts Sucrose) Cholera Medium (Dehydrated), Oxoid Composition

TCBS (Thiosulfate Citrate Bile Salts Sucrose) Cholera Medium (Dehydrated), Oxoid Preparation:
Suspend 88g in 1 litre of distilled water. Boil to dissolve the medium completely. DO NOT AUTOCLAVE.
Pour plates without further heating and dry before use.

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 identification of the various Vibrio species on TCBS Medium is presumptive and further tests are required for confirmation.
Yellow colonies on TCBS Medium will give unsatisfactory oxidase reactions.
Colonies taken from TCBS Medium are `sticky’ and react poorly in slide agglutination tests. Subculture to nutrient agar is required before slide agglutination tests can be carried out.
Some strains of Vibrio vulnificus produce better recovery at 30°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.

Select and identify salmonellae (other than Salmonella Typhi) from food, feed and water samples with Thermo Scientific™ Oxoid™ Modified Brilliant Green Agar (Dehydrated). The modified formula provides improved inhibition of Escherichia coli and Proteus species. The medium has been widely assessed in Europe and has been used in ISO standards.

Brilliant Green Agar (Modified), Oxoid Composition

Brilliant Green Agar (Modified), Oxoid Preparation:
Suspend 52g in 1 litre of distilled water. Heat gently with occasional agitation and bring just to the boil to dissolve the medium completely. DO NOT AUTOCLAVE. Cool to 50°C, 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 at 2-8°C.

Precautions
Lactose-fermenting salmonellae may be present in foods.
Salmonella typhi and Shigella species may not grow on this medium.
Proteus, Citrobacter and Pseudomonas species may mimic enteric pathogens by producing small red colonies.

Determine the plate counts of microorganisms in food, dairy samples, waste water and other material of sanitary importance with Thermo Scientific™ Oxoid™ Plate Count Agar (Dehydrated). Plate Count Agar was developed by Buchbinder et al which is recommended by APHA, AOAC and PHLS. The quality control of Plate Count Agar (APHA) includes testing in accordance with ISO 11133:2014.

Plate Count Agar (Dehydrated), Oxoid Composition

Plate Count Agar (Dehydrated), Oxoid Preparation:
Add 17.5g to 1 litre of distilled water. Dissolve by bringing to the boil with frequent stirring, mix 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 plates at 2-8°C.

Detect microbial deoxyribonuclease enzymes, particularly from staphylococci, with Thermo Scientific™ Oxoid™ DNASE Agar (Dehydrated). A DNase (deoxyribonuclease) is any enzyme that catalyzes the cleavage of phosphodiester linkages of DNA leading to its degradation. The organisms producing DNase enzymes in sufficient quantities to hydrolyze DNA will show clear zones around the colonies. The medium is mainly used in the identification of staphylococci but may also be used for the detection of DNase activity in other organisms.

DNASE Agar, Oxoid Composition

DNASE Agar, Oxoid Preparation:
Suspend 39g 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 of medium at 2-8°C.

Precautions
The DNase reaction for staphylococci is an indication of pathogenicity, it cannot be used as the sole criterion for identification.
Small zones of clearing may be caused by other enzymes or organic acid production.
Other organisms than staphylococci, Serratia and aeromonads can produce DNases.
Once the hydrochloric acid has been applied to the medium the plate must be read within a few minutes and further testing cannot be carried out by re-incubation.
The methyl green must be purified by extraction with chloroform.
Toluidine blue varies in performance according to source.
Merck Toluidine blue 1273 is satisfactory. Note that this dye cannot be used for Gram positive organisms.

Enrich Enterobacteriaceae in bacteriological examination of foods and animal feed stuffs with Thermo Scientific™ Oxoid™ EE Broth (Buffered Glucose Brilliant Green Bile Broth) (Dehydrated). This medium is more inhibitory to non-Enterobacteriaceae than other non-selective media e.g. Mannitol broth or Lactose broth by virtue of the presence of brilliant green and bile salts in the preparation.

EE Broth, Oxoid Composition

EE Broth, Oxoid Preparation:
Add 43.5g to 1 litre of distilled water. Distribute 100ml quantities in 250ml flasks and heat at 100°C for 30 minutes only. Cool rapidly in cold running water. This medium is heat sensitive. 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 medium at 2-8°C.

Precautions
Avoid overheating the medium, especially the double-strength broth.

• Oxoid WL Nutrient Agar is used for the determination of the microbiological flora in brewing and fermentation processes.
• Also available Cycloheximide 0.1% Solution, Part No. SR0222C.

WL Nutrient Agar, Oxoid Composition

WL Nutrient Agar, Oxoid Preparation:
Suspend 75g in 1 litre of distilled water. Bring to the boil to dissolve completely. Sterilise by autoclaving at 121°C for 15 minutes. If required the pH may be adjusted to 6.5 by the addition of 1% sodium bicarbonate solution.

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.

Isolate, enumerate and differentiate urinary pathogens with Thermo Scientific™ Oxoid™ C.L.E.D. Medium (Dehydrated). Cystine-Lactose-Electrolyte-Deficient (CLED) Medium which provides good colonial differentiation, clear diagnostic characteristics and prevents swarming of Proteus spp. due to the electrolyte deficiency in the formulation.

C.L.E.D. Medium, Oxoid Composition

C.L.E.D. Medium, Oxoid Preparation:
Suspend 36.2g 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.

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

Differentiate Enterobacteriaceae according to their ability to ferment lactose, sucrose, and glucose, and to produce hydrogen sulphide using Thermo Scientific™ Oxoid™ Triple Sugar Iron Agar (Dehydrated). The Triple Sugar Iron Agar is based on Kligler Iron Agar, additionally, it contains sucrose for the detection of sucrose fermenting species.

Triple Sugar Iron Agar, Oxoid Composition

Triple Sugar Iron Agar, Oxoid Preparation:
Suspend 65g in 1 litre of distilled water. Bring to the boil to dissolve completely. Mix well and distribute. Sterilise by autoclaving at 121°C for 15 minutes. Allow the medium to set in sloped form with a butt about 1 in.deep.

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.

Baird Parker Agar Base, Oxoid is suitable for the isolation and enumeration of Staphylococcus aureus, with high selectivity and sensitivity. It contains carefully balanced selective inhibitory agents, glycine, lithium, and tellurite, to suppress the growth of most of the bacteria present in foods without inhibiting coagulase-positive staphylococci. The presence of egg yolk emulsion and sodium pyruvate aid the recovery of damaged cells for presumptive identification of Staphylococcus aureus in food specimens.

Baird Parker Agar Base, Oxoid Preparation:

Suspend 6.3g of Baird-Parker Agar Base (RPF) in 90ml of distilled water. Bring to the boil to dissolve completely. Sterilise by autoclaving at 121ºC for 15 minutes. Cool to 48ºC and add 1 vial of RPF Supplement (SR0122A), reconstituted as directed. Mix well and pour plates.

Storage Conditions and Shelf Life
Store the dehydrated medium at 10-30°C and RPF Supplement below 0°C. Use before the expiry date on the label.
Prepared plates of the medium are best used freshly prepared.

Precautions
Regard all suspicious colonies as Staphylococcus aureus regardless of negative reactions in the medium and carry out further tests.
Colonies of some contaminating organisms growing in close proximity to the coagulase positive colonies may partially digest the coagulase halo reaction.

Cultivate and isolate fastidious pathogens and other microorganisms with Thermo Scientific™ Oxoid™ Blood Agar Base No. 2 (Dehydrated). The specially designed formulation meets the need for a nutritious blood agar which permits maximum recovery of delicate organisms without interfering with their hemolytic reactions. Without any additions, the medium can be used for short-term maintenance of stock cultures. And with the addition of blood, the medium becomes suitable for the determination of the hemolytic reactions which are important diagnostic criteria for many organisms.

Blood Agar Base No. 2, Oxoid Composition

Blood Agar Base No. 2, Oxoid Preparation:
Suspend 40g in 1 litre of distilled water. Bring to the boil to dissolve completely. Sterilise by autoclaving at 121°C for 15 minutes. Cool to 45-50°C and add 7% sterile blood.

Mix with gentle rotation and pour into sterile dishes or other containers.

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.

Oxoid Brilliant Green Agar (Kauffmann Medium) is used for increased recovery and selective isolation of Salmonella spp. other than S. Typhi.

• Also available Sulphamandelate Supplement, Part No. SR0087E

Brilliant Green Agar, Oxoid Composition

Brilliant Green Agar, Oxoid Preparation:
Suspend 50g 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 of medium at 2-8°C.

Precautions
Lactose-fermenting salmonellae may be present in foods.
Salmonella typhi and Shigella species may not grow on this medium.
Proteus, Citrobacter and Pseudomonas species may mimic enteric pathogens by producing small red colonies.

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.