Oxoid™ MacConkey Agar No. 3 (Dehydrated) is a selective and differential medium designed for the isolation and differentiation of Gram-negative enteric bacteria, particularly coliform organisms, from clinical, food, and environmental samples. This formulation enhances the differentiation between lactose and non-lactose fermenters while effectively inhibiting Gram-positive organisms.

Supplied in a 25kg dehydrated powder format, it is ideal for high-throughput microbiological laboratories and quality control environments. The medium incorporates a specially prepared fraction of bile salts and crystal violet to suppress Gram-positive bacteria, while lactose and neutral red enable differentiation based on lactose fermentation.

Key Features:

• Form: Dehydrated powder
• Weight: 25kg
• Application: Isolation and differentiation of Gram-negative enteric bacteria in clinical, food, and environmental samples
• Selective Agents: Bile salts No. 3 and crystal violet to inhibit Gram-positive organisms
• Differentiation: Lactose fermenters (e.g., Escherichia coli) produce red colonies with bile precipitation; non-lactose fermenters (e.g., Salmonella, Shigella) form straw-colored colonies
• Composition (per liter): Peptone (20.0g), Lactose (10.0g), Bile salts No. 3 (1.5g), Sodium chloride (5.0g), Neutral red (0.03g), Crystal violet (0.001g), Agar (15.0g)
• Preparation: Suspend 51.5g in 1 liter of distilled water, bring to the boil with frequent agitation to dissolve completely. Sterilize by autoclaving at 121°C for 15 minutes. Cool to 50°C, mix well, and pour into sterile Petri dishes.
• Yield: Approximately 485 liters of prepared medium
• pH: 7.1 ± 0.2 at 25°C
• Standards: Recommended by the American Public Health Association for the examination of food and water samples for coliforms and enteric pathogens

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Oxoid™ MacConkey Agar No. 3 (Dehydrated) is a selective and differential medium designed for the isolation and differentiation of Gram-negative enteric bacteria, particularly coliform organisms, from clinical, food, and environmental samples. This formulation enhances the differentiation between lactose and non-lactose fermenters while effectively inhibiting Gram-positive organisms.

Supplied in a 25kg dehydrated powder format, it is ideal for high-throughput microbiological laboratories and quality control environments. The medium incorporates a specially prepared fraction of bile salts and crystal violet to suppress Gram-positive bacteria, while lactose and neutral red enable differentiation based on lactose fermentation.

Key Features:

• Form: Dehydrated powder
• Weight: 25kg
• Application: Isolation and differentiation of Gram-negative enteric bacteria in clinical, food, and environmental samples
• Selective Agents: Bile salts No. 3 and crystal violet to inhibit Gram-positive organisms
• Differentiation: Lactose fermenters (e.g., Escherichia coli) produce red colonies with bile precipitation; non-lactose fermenters (e.g., Salmonella, Shigella) form straw-colored colonies
• Composition (per liter): Peptone (20.0g), Lactose (10.0g), Bile salts No. 3 (1.5g), Sodium chloride (5.0g), Neutral red (0.03g), Crystal violet (0.001g), Agar (15.0g)
• Preparation: Suspend 51.5g in 1 liter of distilled water, bring to the boil with frequent agitation to dissolve completely. Sterilize by autoclaving at 121°C for 15 minutes. Cool to 50°C, mix well, and pour into sterile Petri dishes.
• Yield: Approximately 485 liters of prepared medium
• pH: 7.1 ± 0.2 at 25°C
• Standards: Recommended by the American Public Health Association for the examination of food and water samples for coliforms and enteric pathogens

Download SDS