Sigma-Aldrich Middlebrook OADC Growth Supplement, 50 mL

Sigma-Aldrich Middlebrook OADC Growth Supplement (50 mL)

Middlebrook OADC Growth Supplement is a highly enriched supplement added to Middlebrook agar-based (7H10, 7H11) and broth-based (7H9) media to promote the isolation and cultivation of Mycobacteria, including Mycobacterium tuberculosis and other slow-growing Mycobacterium species. This supplement provides essential growth factors and protection from toxic substances to ensure optimal growth conditions for Mycobacteria.

Key Features

1. Nutrient-Rich Supplement
   • Contains oleic acid, albumin, dextrose, catalase, and sodium chloride to support the growth and metabolism of Mycobacteria.
2. Essential for Mycobacterial Growth
   • Supplies long-chain fatty acids (e.g., oleic acid) essential for Mycobacterial metabolism.
   • Neutralizes toxic fatty acids and peroxides that can inhibit Mycobacteria.
3. Compatible with Multiple Media
   • Added to Middlebrook 7H10, 7H11 agar, and 7H9 broth for enhanced growth.
4. Promotes Robust Growth of Fastidious Organisms
   • Improves the isolation and recovery of slow-growing Mycobacterium tuberculosis and other species from clinical, environmental, and food samples.
5. Convenient and Easy to Use
   • Ready-to-use format simplifies media preparation and ensures reproducibility.

Composition (per vial, 50 mL)

Applications

1. Isolation and Cultivation of Mycobacteria
   • Added to Middlebrook 7H9 Broth, 7H10 Agar, or 7H11 Agar to promote optimal growth of Mycobacterium species.
2. Clinical Diagnostics
   • Used in laboratories to isolate and culture Mycobacterium tuberculosis from clinical specimens (e.g., sputum, urine, biopsies).
3. Environmental Testing
   • Applied to detect and culture Mycobacteria from environmental water and soil samples.
4. Food and Beverage Microbiology
   • Ensures the recovery and detection of Mycobacteria in food products to monitor contamination.
5. Research Applications
   • Used for cultivating and maintaining Mycobacterial strains in vaccine development, drug resistance studies, and metabolic assays.

Mechanism of Action

• Oleic Acid: Provides essential fatty acids required for the metabolism of Mycobacteria.
• Bovine Albumin:
  • Binds and neutralizes toxic fatty acids.
  • Protects Mycobacteria from toxic agents present in the medium.
• Dextrose: Acts as a fermentable carbohydrate and primary energy source for growth.
• Catalase: Neutralizes toxic peroxides that could inhibit Mycobacterial growth.
• Sodium Chloride: Maintains osmotic balance in the medium.

Preparation Instructions

1. For Solid Media (Middlebrook 7H10 or 7H11 Agar):
   • Prepare the agar medium as per the manufacturer's instructions.
   • Cool the sterilized medium to 45–50°C.
   • Aseptically add Middlebrook OADC Growth Supplement (50 mL per liter of prepared medium).
   • Mix thoroughly and dispense into sterile Petri plates or tubes.
2. For Broth Media (Middlebrook 7H9):
   • Prepare and autoclave the 7H9 broth.
   • Cool the broth to 45–50°C.
   • Aseptically add Middlebrook OADC Growth Supplement (50 mL per liter of broth).
   • Mix thoroughly before dispensing.

Advantages

1. Improved Growth Performance
   • Provides essential nutrients and growth factors for fastidious Mycobacteria.
2. Neutralizes Toxic Agents
   • Albumin and catalase protect Mycobacteria from toxic free fatty acids and peroxides.
3. Versatile Application
   • Compatible with solid and liquid media (7H9, 7H10, 7H11).
4. Reproducibility
   • Standardized supplement ensures consistent growth performance.
5. Cost-Effective
   • Reduces the need for additional supplements, saving preparation time and cost.

Comparison of Middlebrook Media Supplements

Quality Control

Storage and Shelf Life

• Store the supplement at 2–8°C in its original container.
• Protect from light to maintain activity.
• Use before the expiration date indicated on the label.

The Middlebrook OADC Growth Supplement is an essential component for cultivating Mycobacterium tuberculosis and related species, ensuring robust growth and high recovery rates in both clinical diagnostics and research settings.