Thermo Scientific™ Oxoid™ MLCB Agar (Dehydrated), 500G

The Thermo Scientific™ Oxoid™ MLCB Agar (Dehydrated) is a selective culture medium formulated for the isolation of Salmonella species (excluding Salmonella Typhi and Salmonella Paratyphi A) from fecal and food samples. Based on the formulation developed by Inoue et al., this medium is optimized for the reliable detection of hydrogen sulphide (H₂S)-producing Salmonella strains, even at low concentrations.

MLCB Agar supports the growth of salmonellae while suppressing competing flora, enabling clear differentiation through distinctive colony morphology. Typical Salmonella colonies appear as large purple-black colonies due to hydrogen sulphide production, facilitating rapid and confident identification. The medium is particularly useful for detecting lactose-fermenting Salmonella strains, such as Salmonella arizonae, as it does not rely on lactose fermentation for differentiation.

Designed for clinical, food safety, and environmental microbiology laboratories, this medium is suitable for both direct inoculation and enrichment culture workflows, supporting routine screening and regulatory testing applications.

Key Features

• Selective medium for isolation of Salmonella spp. (excluding Typhi & Paratyphi A)
• Enables detection of hydrogen sulphide (H₂S)-producing strains via black colony formation
• Supports identification of lactose-fermenting Salmonella strains
• Distinctive colony morphology for easy visual differentiation
• Suitable for fecal and food sample analysis
• Can be used with direct plating or enrichment cultures
• Manufactured under recognized industrial standards (NMKL compliance)
• High-quality dehydrated medium from Thermo Scientific™ Oxoid™

Applications

• Clinical microbiology – detection of Salmonella in fecal samples
• Food microbiology – screening of food products for Salmonella contamination
• Environmental testing – monitoring of water and environmental samples
• Public health laboratories – outbreak investigation and surveillance
• Quality control in food and beverage industries

Principle of the Method

MLCB Agar differentiates Salmonella species based on mannitol fermentation, lysine decarboxylation, and hydrogen sulphide production:

• Hydrogen sulphide production results in black-centered colonies
• Mannitol utilization lowers pH, triggering lysine decarboxylation, stabilizing the medium
• Typical Salmonella colonies appear as purple-black colonies
• Atypical strains may appear mauve-grey with a central black “bull’s eye”

This combination of biochemical reactions ensures accurate identification and differentiation of Salmonella species from background flora.

Technical Specifications

Advantages

The Thermo Scientific™ Oxoid™ MLCB Agar provides high selectivity and clear differentiation, making it particularly valuable for laboratories dealing with complex sample matrices such as food and fecal specimens. Its ability to detect low levels of hydrogen sulphide-producing Salmonella ensures high sensitivity, while the distinct colony morphology reduces misidentification risks.

Unlike lactose-dependent media, MLCB Agar allows reliable detection of atypical and lactose-fermenting Salmonella strains, enhancing diagnostic accuracy in diverse testing scenarios.

The Thermo Scientific™ Oxoid™ MLCB Agar (Dehydrated) is a reliable and high-performance selective medium for the isolation and differentiation of Salmonella species in clinical and food microbiology applications. With its robust formulation, clear visual differentiation, and compliance with recognized standards, it is an essential tool for laboratories focused on food safety, public health, and microbiological quality control.