Plate Count Agar (PCA): Reliable Standard for Microbial Enumeration in Food and Water Testing
Catalog Number: AS-1328
Introduction
Plate Count Agar (PCA), also known as Standard Methods Agar or Tryptone Glucose Yeast Extract Agar, is a universally recognized microbiological growth medium. It is widely used for the enumeration of viable aerobic microorganisms in a variety of samples, including food, beverages, water, and environmental materials. With its balanced nutrient composition, PCA supports the growth of a broad spectrum of bacteria, making it an essential tool for ensuring product safety and quality in numerous industries.
Key Features
Versatile Application: Ideal for total viable count in food, water, dairy products, and environmental samples.
Nutrient-Rich Composition: Provides essential nutrients to support diverse bacterial growth.
Compliance with Standards: Meets international guidelines such as ISO 4833, FDA-BAM, and APHA for microbial enumeration.
Reliable and Consistent Results: Ensures accurate colony counts for quality control and regulatory compliance.
Easy Preparation: Straightforward protocol suitable for routine laboratory use.
Composition
| Ingredient | Concentration (g/L) |
|---|---|
| Tryptone | 5.0 |
| Yeast Extract | 2.5 |
| Glucose (Dextrose) | 1.0 |
| Agar | 15.0 |
| Total | 23.5 |
Final pH (25°C): 7.0 ± 0.2
Applications
1. Food and Beverage Industry
Microbial Load Assessment: Determines the total viable bacterial count in products like meat, dairy, poultry, fruits, and vegetables.
Quality Assurance: Monitors sanitation and hygiene practices during production and processing.
Shelf-Life Studies: Evaluates microbial growth over time to establish expiration dates.
2. Water Testing
Drinking Water Safety: Assesses the microbial quality of potable water to ensure safety standards.
Environmental Monitoring: Used in testing recreational waters, wastewater, and effluents for bacterial contamination.
3. Pharmaceutical and Cosmetics Industries
Microbial Limit Testing: Ensures products meet USP and EP microbial count requirements.
Process Water Testing: Monitors microbial content in water used during manufacturing processes.
4. Environmental Sampling
Surface and Air Monitoring: Detects bacterial presence on surfaces and in the air within controlled environments.
Advantages
Broad Spectrum Growth: Supports a wide range of non-fastidious, aerobic bacteria.
Standardized Results: Provides consistent methodology for regulatory and compliance purposes.
High Clarity: Transparent medium facilitates easy colony visualization and counting.
Cost-Effective: Affordable solution for routine microbial enumeration.
Preparation Instructions
Weigh the Medium: Suspend 23.5 grams of Plate Count Agar powder in 1 liter of distilled or deionized water.
Mix: Stir the mixture until the powder is fully dispersed.
Heat: Gently heat the solution with frequent agitation until it reaches boiling and the medium is completely dissolved.
Sterilize: Autoclave at 121°C for 15 minutes.
Cool: Allow the sterilized medium to cool to 45-50°C.
Pour Plates: Aseptically dispense the medium into sterile Petri dishes.
Solidify: Let the agar solidify at room temperature.
Store Plates: If not used immediately, store the plates in a refrigerator at 2-8°C.
Usage Guidelines
Sample Dilution: Prepare serial dilutions of your sample to achieve countable colonies (30-300 colonies per plate).
Inoculation: Apply 1 mL of the appropriate dilution onto the agar surface or mix with molten agar (pour plate method).
Incubation:
Temperature: Incubate plates at 35±1°C.
Time: Standard incubation period is 48±2 hours.
Conditions: Incubate in an aerobic environment, plates inverted.
Counting Colonies: After incubation, count colonies using a colony counter or manually.
Quality Control
Recommended Control Strains:
| Organism | ATCC Number | Expected Results |
|---|---|---|
| Escherichia coli | ATCC® 25922™ | Growth |
| Staphylococcus aureus | ATCC® 25923™ | Growth |
| Bacillus subtilis | ATCC® 6633™ | Growth |
| Pseudomonas aeruginosa | ATCC® 27853™ | Growth |
Storage and Shelf Life
Dehydrated Medium:
Storage Temperature: 10-30°C
Conditions: Keep container tightly closed in a dry place.
Shelf Life: Refer to the expiration date on the label.
Prepared Plates:
Storage Temperature: 2-8°C
Protect from: Light and dehydration.
Shelf Life: Use within 7 days for optimal performance.
