Baird Parker Agar Base A1 Quality – HX-Media

Baird Parker Agar Base – HX-Media

Product Overview

Baird Parker Agar Base is a selective and differential microbiological culture medium specifically formulated for the isolation and enumeration of Staphylococcus aureus from a wide range of samples including food, dairy products, cosmetics, pharmaceuticals, clinical specimens, and environmental sources. It is widely regarded as one of the standard media for coagulase-positive staphylococci detection, recommended by ISO, FDA, and APHA methods.

Baird Parker Agar is designed to exploit the unique physiological and biochemical characteristics of Staphylococcus aureus, enabling both selective inhibition of competing flora and distinct colony differentiation. The base medium is typically supplemented with Egg Yolk Tellurite Emulsion prior to use, which enhances both selectivity and differentiation.

The formulation contains enzymatic digests of casein and yeast extract, providing a rich supply of amino acids, peptides, vitamins, and growth factors necessary for the rapid and luxuriant growth of staphylococci. Sodium pyruvate is included to support the recovery of injured or stressed cells, particularly those exposed to heat or preservation processes in food samples.

Lithium chloride and glycine act as selective agents, inhibiting the growth of most Gram-negative bacteria and non-staphylococcal organisms, thereby enhancing the selectivity of the medium for staphylococci.

A key differential feature of the medium arises from the reduction of potassium tellurite to tellurium, which results in the formation of black or gray colonies. In addition, the presence of egg yolk allows detection of lecithinase activity, leading to the formation of clear zones (halos) around colonies, a characteristic feature of Staphylococcus aureus.

Typical colonies of Staphylococcus aureus on Baird Parker Agar appear as black, shiny, convex colonies surrounded by clear zones due to lecithinase activity, often with an additional opaque zone due to lipase activity, providing a reliable visual basis for presumptive identification.

Due to its high specificity, clear differentiation, and ability to recover injured cells, Baird Parker Agar Base is extensively used in food safety testing, pharmaceutical quality control, and hygiene monitoring, ensuring compliance with regulatory microbiological standards.

🎯 Applications

• Food and dairy microbiology (pathogen detection)
• Pharmaceutical and cosmetic testing
• Environmental and surface hygiene monitoring
• Clinical microbiology (selective isolation)
• Detection of coagulase-positive staphylococci
• Quality control laboratories

🔬 Key Features

• Highly selective and differential medium
• Specifically designed for Staphylococcus aureus detection
• Produces distinct black colonies with clear halos
• Supports recovery of injured/stressed cells
• Complies with ISO, FDA, APHA standards
• High specificity and reproducibility
• Suitable for routine and regulatory testing

🧪 Composition (Typical)

• Casein Enzymatic Digest : 10.0g
• Yeast Extract : 1.0g
• Meat Extract : 5.0g
• Sodium Pyruvate : 10.0g
• Glycine : 12.0g
• Lithium Chloride : 5.0g
• Agar : 12.0–20.0g
• Final pH: 7.0 ± 0.2 at 25°C

🛠️ How to Use

1. Suspend the required quantity of Baird Parker Agar Base in distilled water.
2. Heat with agitation to dissolve completely.
3. Sterilize by autoclaving at 121°C for 15 minutes.
4. Cool to 45–50°C.
5. Aseptically add Egg Yolk Tellurite Emulsion.
6. Mix gently and pour into sterile Petri plates.
7. Allow medium to solidify.
8. Inoculate sample using spread plate or streak method.
9. Incubate at 35–37°C for 24–48 hours.

⏳Storage and Shelf Life

• Store dehydrated medium at 10–30°C, protected from moisture
• Keep tightly closed after use
• Prepared plates (with supplement) should be used fresh or within 24–48 hours
• Shelf life: 2–3 years (dehydrated form)

👍 Ideal For

✔ Detecting and enumerating Staphylococcus aureus

✔ Testing food, environmental, cosmetic, and clinical samples

✔ Confirming coagulase-positive staphylococci

✔ Workflows requiring highly selective and differential media