The Columbia CNA Agar (Sheep blood 5%) is a highly selective culture medium specifically designed for the isolation and differentiation of Gram-positive cocci, such as streptococci, staphylococci, and pneumococci, from clinical and non-clinical samples. Thanks to its unique formulation, this agar is essential for microbiological laboratories that require precise and reliable results.

Product Features

• Format: Pack of 20 plates of 90 mm


• Composition: Contains 5% defibrinated sheep blood, special peptides, starch, sodium chloride, colistin sulfate, and nalidixic acid.


• Final pH: 7.3 ± 0.2, ideal for the growth of demanding microorganisms.

Operating Principle

The Columbia CNA Agar utilizes a combination of nutrients and selective agents to promote the growth of Gram-positive bacteria while inhibiting Gram-negative bacteria. Here’s how it works:

• Peptospecial: Source of nitrogen, carbon, and sulfur, essential for microbial growth.


• Sodium Chloride: Maintains the osmotic balance of the medium.


• Colistin and Nalidixic Acid: Selective agents that inhibit the growth of Gram-negative bacteria.


• Defibrinated Sheep Blood: Provides additional nutrients and allows observation of hemolytic reactions.


• Agar: Solidifying agent that allows the formation of well-defined colonies.

Usage Instructions

To achieve optimal results, follow these instructions:

1. Inoculate the plates by streaking the sample on the surface of the medium with a sterile loop.


2. Incubate at 36 ± 1°C for a period of 18-48 hours.


3. Use an aerobic, anaerobic, or microaerophilic atmosphere depending on the sample's needs.

Applications

The Columbia CNA Agar is particularly useful in:

• Clinical laboratories for the analysis of biological samples.


• Microbiology studies for the search of pathogenic bacteria.


• Quality control in food and pharmaceutical industries.

Conclusion

Choosing the Columbia CNA Agar (Sheep blood 5%) means ensuring high-quality microbiological analysis. Its advanced formulation and ability to effectively isolate Gram-positive cocci make it an indispensable product for any laboratory dealing with microbiology.