Microbiology

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.

Thermo Scientific™ Oxoid Defibrinated Horse Blood is a blood product.

**This product is not available at the moment.

Thermo Scientific™ Oxoid Defibrinated Horse Blood is a blood product.

**This product is not available at the moment.

Thermo Scientific™ Oxoid Defibrinated Sheep Blood is a blood product.

**This product is not available at the moment.

Oxoid Rogosa Agar is used for the selective isolation and enumeration of lactobacilli.

Rogosa Agar, Oxoid Composition

Rogosa Agar, Oxoid Preparation:
Suspend 82g in 1 litre of distilled water and bring to the boil to dissolve completely. Add 1.32ml glacial acetic acid and mix thoroughly. Heat to 90-100°C for 2-3 minutes with frequent agitation. Distribute into sterile tubes, Petri dishes or bottles.
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
Lactobacillus carnis does not grow on this medium.
All colonies must be tested by Gram stain and catalase test before carrying out further identification tests.

• Oxoid Dermasel Agar Base is used for primary isolation and identification of dermatophyte fungi.
• Also available Dermasel Selective Supplement, Part No. SR0075E.

Dermasel Agar Base, Oxoid Composition

Dermasel Agar, Oxoid Preparation:
Suspend 44.5g in 1 litre of distilled water and heat gently to dissolve completely. Add the contents of 1 vial of Dermasel Selective Supplement SR0075, reconstituted as directed in the product insert, to each 500ml of medium to give a level of cycloheximide 0.4g/l and chloramphenicol 0.05g/l. Mix gently and sterilise by autoclaving at 121°C for 10 minutes. Avoid overheating at any time.

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
This medium should not be used if agents causing systemic mycoses are being sought⁹. If such agents are suspected e.g. cryptococcus, histoplasma etc., either Dermasel Agar Base without antibiotic supplement must be used in parallel or Brain Heart Infusion Agar CM0375.
If the fungal agent sought is suspected to be nutritionally fastidious, the use of Brain Heart Infusion Agar is particularly helpful.

Oxoid Dermasel Selective Supplement is used for Dermasel Medium, Part No. CM0539B.

• Each vial supplements 500mL of medium

Dermasel Selective Supplement, Oxoid Composition

Dermasel Agar, Oxoid Preparation:
Suspend 44.5g in 1 litre of distilled water and heat gently to dissolve completely. Add the contents of 1 vial of Dermasel Selective Supplement SR0075, reconstituted as directed in the product insert, to each 500ml of medium to give a level of cycloheximide 0.4g/l and chloramphenicol 0.05g/l. Mix gently and sterilise by autoclaving at 121°C for 10 minutes. Avoid overheating at any time.

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
This medium should not be used if agents causing systemic mycoses are being sought⁹. If such agents are suspected e.g. cryptococcus, histoplasma etc., either Dermasel Agar Base without antibiotic supplement must be used in parallel or Brain Heart Infusion Agar CM0375.
If the fungal agent sought is suspected to be nutritionally fastidious, the use of Brain Heart Infusion Agar is particularly helpful.
Dermasel Selective Supplement SR0075 contains a toxic concentration of cycloheximide. Note the precautions to be taken under HAZARDS.

Isolate, enumerate and differentiate coliforms in dairy products with differential Thermo Scientific™ Oxoid™ Desoxycholate Agar (Dehydrated). The medium is also used for the isolation of enteric pathogens from rectal swabs, feces or other specimens. Differentiation of coliforms is based on the fermentation of lactose. Lactose fermenting bacteria form pink colored colonies while non-lactose fermenters form straw colored colonies.

Desoxycholate Agar, Oxoid Composition

Desoxycholate Agar, Oxoid Preparation:
Suspend 45g in 1 litre of distilled water. Bring to the boil over gauze and flame to dissolve the medium completely. Agitate to prevent charring.
THIS MEDIUM IS HEAT SENSITIVE. AVOID EXCESSIVE OR PROLONGED HEATING DURING RECONSTITUTION. DO NOT AUTOCLAVE OR REMELT.

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.

An improved medium, based on the Hynes modification of Leifsons medium for the isolation of Salmonellae and Shigellae. The improvement gives larger and more numerous colonies of Shigella species which can easily be picked off and emulsified in saline for slide agglutination tests.

Desoxycholate Citrate Agar (Hynes), Oxoid Composition

Desoxycholate Citrate Agar (Hynes), Oxoid Preparation:
Suspend 52g in 1 litre of distilled water. Bring to the boil over gauze and flame, to dissolve completely. Agitate to prevent charring. Cool to approximately 50°C and pour into sterile Petri dishes. Dry the agar surface before use.
THIS MEDIUM IS HEAT SENSITIVE: AVOID EXCESSIVE OR PROLONGED HEATING DURING RECONSTITUTION. DO NOT AUTOCLAVE OR REMELT.

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
The medium is best used freshly prepared.
Stock cultures of Shigella species may become predominantly in the R-phase when subcultured away from DCA media. Such cultures are difficult to use for control purposes without first heavily streaking the cultures on DCA plates and picking off the few S-phase colonies i.e. the macro-colonies on the agar surface, for further subculture.
When making biochemical tests on colonies picked from the surface of DCA plates, purity subcultures should be carried out because the colony may be contaminated with Escherichia coli present as micro-colonies.

Oxoid Desoxycholate Citrate Agar is a differential medium for enumeration of coliforms and the isolation of enteric pathogens.

Desoxycholate Citrate Agar, Oxoid Composition

Desoxycholate Citrate Agar, Oxoid Preparation:
Suspend 48.5g in 1 litre of distilled water. With frequent agitation bring to the boil over a gauze and flame to dissolve completely. Mix well and pour plates immediately. Dry the agar surface before use.

THIS MEDIUM IS HEAT SENSITIVE. AVOID EXCESSIVE OR PROLONGED HEATING DURING RECONSTITUTION. DO NOT AUTOCLAVE, OR REMELT.

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
The medium is best used freshly prepared.
Stock cultures of Shigella species may become predominantly in the R-phase when subcultured away from DCA media. Such cultures are difficult to use for control purposes without first heavily streaking the cultures on DCA plates and picking off the few S-phase colonies i.e. the macro-colonies on the agar surface, for further subculture.
When making biochemical tests on colonies picked from the surface of DCA plates, purity subcultures should be carried out because the colony may be contaminated with Escherichia coli present as micro-colonies.

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

Oxoid Dextrose Tryptone Agar is used for detection and enumeration of thermophilic and mesophilic microorganisms in food.

Dextrose Tryptone Agar, Oxoid Composition

Dextrose Tryptone Agar, Oxoid Preparation:
Suspend 27g 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 agar plates at 2-8°C.

Precautions
Incubation at 55°C must be carried out under humid conditions e.g. wrapped dishes or in a high humidity environment.

Oxoid Dextrose Tryptone Broth is used for detection and enumeration of thermophilic and mesophilic microorganisms in food.

Dextrose Tryptone Broth, Oxoid Composition

Dextrose Tryptone Broth, Oxoid Preparation:
Add 15g to 1 litre of distilled water. 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 broth below 25°C.

Description

This DG 18 (Dichloran glycerol chloramphenicol) agar (base) is tested according to ISO 21527 and FDA-BAM GranuCult®. DG 18 Agar is suitable to enumerate and isolate xenophilic moulds from dried and semi-dried foods such as dried fruits, spices, confectionery, cereals, nuts, and dried meat and fish products.

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 Dichloran-Glycerol (DG18) Agar Base is a selective low water activity (aw) medium for xerophilic molds from dried and semi-dried foods.
• Also available Chloramphenicol Selective Supplement, Part No. SR0078E and Chloramphenicol Selective Supplement, Part No. SR0078H.

Dichloran-Glycerol (DG18) Agar Base, Oxoid Composition

Dichloran-Glycerol (DG18) Agar, Oxoid Preparation:
Suspend 15.75g in 500ml (31.5g/l) of distilled water and heat to dissolve completely. Add 110g per 500ml (220g/l) of Glycerol (Analytical Reagent grade). Reconstitute one vial SR0078E per 500ml medium or one vial SR0078H per 2 litres medium, as directed. Add the vial contents to the DG18 Agar 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.

Precautions
The dichloran compound used in this medium is Botran® 2,6-Dichloro-4-Nitro-Analine (CAS: 99-30-9).