13-50mm diameters
0.22 / 0.45 / 0.8 μm pore sizes
White or black grid
3×3 mm grid interval
With or without absorbent pad
Gamma sterilized
Individually packed
Availability: In Stock
Gridded Membrane Filter for Colony Counting & Sterility Testing
Description
What Is a gridded membrane filter?
A gridded membrane filter is a membrane filter with a printed grid pattern on its surface, designed to facilitate the counting of bacterial colonies, particles, and microorganisms under a microscope. The grid divides the filtration area into small, equal squares-typically 3×3 mm-making it easier to count colonies accurately, especially when they are crowded or overlapping.
Hawach gridded membrane filters are manufactured from mixed cellulose esters (MCE) and are available in both white and black membranes with contrasting grid colors. A gridded membrane filter is widely used in colony counting, particle testing, microscopy, and sterility testing across pharmaceutical, food, beverage, and environmental laboratories.
Gridded membrane filter – Complete Specification Range
Hawach gridded membrane filters are available in a comprehensive range of sizes and configurations to meet diverse laboratory requirements. All filters are sterile gridded membrane filters, gamma irradiated (SAL 10⁻⁶), and individually packaged for immediate use.
Available Options:
• Diameters: 13mm, 25mm, 28mm, 47mm, 50mm
• Pore sizes: 0.22μm, 0.45μm, 0.8μm
• Membrane color: White (black grid) / Black (white grid)
• Absorbent pad: Available with or without (47mm only)
• Packaging: 30-200 pcs/pack, individually wrapped (sterile)
How Does a gridded membrane filter Work?
A gridded membrane filter works by passing a liquid sample through the membrane under vacuum or pressure. Microorganisms and particles larger than the pore size are retained on the membrane surface. The filter is then placed on an agar plate or absorbent pad and incubated. Colonies develop on the membrane surface, and the grid pattern helps count them accurately.
The grid does not inhibit colony growth-it only serves as a visual aid for counting. For samples with high colony density, the gridded membrane filter makes it possible to count colonies that would otherwise overlap and be difficult to distinguish.
Sterile gridded membrane filter for Pharmaceutical QC
For laboratories requiring ready-to-use sterility, Hawach offers sterile gridded membrane filters that are gamma irradiated (SAL 10⁻⁶) and individually packaged. A sterile gridded membrane filter eliminates the need for autoclaving, reduces contamination risk, and saves valuable preparation time.
A sterile gridded membrane filter is recommended for:
- Pharmaceutical quality control (QC) laboratories
- Clinical microbiology and diagnostic labs
- Cleanroom and environmental monitoring
- Food and beverage sterility testing
Material Advantages
Hawach gridded membrane filters are manufactured from MCE (Mixed Cellulose Esters), a blend of nitrocellulose and cellulose acetate. An MCE gridded membrane filter offers excellent bacterial retention, high flow rates, and compatibility with standard microbiological methods. MCE is the most widely used membrane material for water testing, sterility testing, and general microbiology applications.
The grid is printed with non-toxic, bio-compatible ink that does not interfere with colony growth or particle analysis. All sterile gridded membrane filters are gamma sterilized to ensure ready-to-use sterility.
Why Choose a gridded membrane filter?
Accurate Colony Counting
The 3×3 mm grid pattern allows for systematic counting of colonies, reducing counting errors and improving reproducibility.
Efficient Particle Analysis
For particle testing and microscopy, the grid provides reference points for size estimation and spatial distribution analysis.
Compatible with Automated Systems
gridded membrane filters are compatible with automated colony counters, making high-throughput enumeration faster and more consistent.
Trusted Microbiology Standard
gridded membrane filters are the standard choice for coliform bacteria testing in drinking water, wastewater, and food safety laboratories worldwide.
Applications of gridded membrane filters
Colony Counting
Standard method for enumerating bacterial colonies in water, food, beverage, and pharmaceutical samples.
Water Testing
Detection and enumeration of coliform bacteria, E. coli, and total bacteria in drinking water and wastewater.
Sterility Testing
Pharmaceutical QC, bioburden determination, and microbial limit testing in GMP environments.
Particle Testing & Microscopy
Particle analysis, microscopy, and environmental monitoring applications.
Food & Beverage Microbiology
Microbiological quality control of beverages, dairy products, and processed foods.
Cosmetics & Pharmaceutical QC
Microbial testing of cosmetic products, raw materials, and finished pharmaceuticals.
How to Choose the Right gridded membrane filter
Pore Size Selection:
- 22 μm:Recommended for bacteria retention and sterility testing. Captures most bacteria including Pseudomonas and smaller species.
- 45 μm:Standard for general water testing, coliform bacteria enumeration, and colony counting. Most commonly used pore size.
- 8 μm:Used for yeast, mold, and larger particles; also suitable for fast filtration of samples with high particulate loads.
Diameter Selection:
- 13mm / 25mm:Small-volume samples, syringe filters, and field testing
- 47mm:Standard for most microbiology applications, water testing, and sterility testing
- 50mm:Compatible with specific filter holders and automated systems
Grid Color Selection:
- White membrane with black grid:Best for dark/colored samples where white colonies need contrast.
- Black membrane with white grid:Best for light/transparent samples (e.g., drinking water, clear liquids) where colonies appear dark.
Absorbent Pad:
- With pad:Recommended for microbiology applications where the filter is placed directly on the agar surface.
- Without pad:Used with standard filter funnels and holders.
Technical Specifications
| Membrane Material | MCE (Mixed Cellulose Esters) |
| Diameters | 13mm, 25mm, 28mm, 47mm, 50mm |
| Pore Sizes | 0.22μm, 0.45μm, 0.8μm |
| Grid Interval | 3 × 3 mm |
| Membrane / Grid Colors | White membrane with black grid / Black membrane with white grid |
| Absorbent Pad | Available with or without (47mm only) |
| Sterility | Gamma irradiated, SAL 10⁻⁶ |
| Packaging | Individually packed, sterile |
| pH Range | 4.0 – 8.0 |
| Maximum Operating Temperature | 130°C |
Ordering Information – gridded membrane filter
White Membrane, Black Grid (Without Absorbent Pad)
| Cat. No. | Diameter | Pore Size | Color | Grid | Packaging |
| 11152001 | 13mm | 0.22μm | White | Black | 200 pcs/pk |
| 11152002 | 13mm | 0.45μm | White | Black | 200 pcs/pk |
| 11152003 | 13mm | 0.8μm | White | Black | 200 pcs/pk |
| 11152004 | 25mm | 0.22μm | White | Black | 100 pcs/pk |
| 11152005 | 25mm | 0.45μm | White | Black | 100 pcs/pk |
| 11152006 | 25mm | 0.8μm | White | Black | 100 pcs/pk |
| 11152007 | 28mm | 0.22μm | White | Black | 100 pcs/pk |
| 11152008 | 28mm | 0.45μm | White | Black | 100 pcs/pk |
| 11152009 | 28mm | 0.8μm | White | Black | 100 pcs/pk |
| 11152010 | 47mm | 0.22μm | White | Black | 100 pcs/pk |
| 11152011 | 47mm | 0.45μm | White | Black | 100 pcs/pk |
| 11152012 | 47mm | 0.8μm | White | Black | 100 pcs/pk |
| 11152013 | 50mm | 0.22μm | White | Black | 100 pcs/pk |
| 11152014 | 50mm | 0.45μm | White | Black | 100 pcs/pk |
| 11152015 | 50mm | 0.8μm | White | Black | 100 pcs/pk |
White Membrane, Black Grid – With Absorbent Pad (47mm only)
| Cat. No. | Diameter | Pore Size | Color | Grid | Packaging |
| 11152016 | 47mm | 0.22μm | White | Black | 30 pcs/pk |
| 11152017 | 47mm | 0.45μm | White | Black | 30 pcs/pk |
| 11152018 | 47mm | 0.8μm | White | Black | 30 pcs/pk |
Black Membrane, White Grid (Without Absorbent Pad)
| Cat. No. | Diameter | Pore Size | Color | Grid | Packaging |
| 11152019 | 13mm | 0.22μm | Black | White | 200 pcs/pk |
| 11152020 | 13mm | 0.45μm | Black | White | 200 pcs/pk |
| 11152021 | 13mm | 0.8μm | Black | White | 200 pcs/pk |
| 11152022 | 25mm | 0.22μm | Black | White | 100 pcs/pk |
| 11152023 | 25mm | 0.45μm | Black | White | 100 pcs/pk |
| 11152024 | 25mm | 0.8μm | Black | White | 100 pcs/pk |
| 11152025 | 47mm | 0.22μm | Black | White | 100 pcs/pk |
| 11152026 | 47mm | 0.45μm | Black | White | 100 pcs/pk |
| 11152027 | 47mm | 0.8μm | Black | White | 100 pcs/pk |
| 11152028 | 50mm | 0.22μm | Black | White | 100 pcs/pk |
| 11152029 | 50mm | 0.45μm | Black | White | 100 pcs/pk |
| 11152030 | 50mm | 0.8μm | Black | White | 100 pcs/pk |
Black Membrane, White Grid – With Absorbent Pad (47mm only)
| Cat. No. | Diameter | Pore Size | Color | Grid | Packaging |
| 11152031 | 47mm | 0.22μm | Black | White | 30 pcs/pk |
| 11152032 | 47mm | 0.45μm | Black | White | 30 pcs/pk |
| 11152033 | 47mm | 0.8μm | Black | White | 30 pcs/pk |
All filters are sterile, gamma irradiated (SAL 10⁻⁶), and individually packaged. Contact our sales team for bulk orders and custom specifications.
Download PDF Datasheet
Frequently Asked Questions
What is a gridded membrane filter used for?
A gridded membrane filter is used for colony counting, particle testing, microscopy, and sterility testing. The grid pattern helps microbiologists count bacterial colonies accurately.
What pore sizes are available for gridded membrane filters?
Hawach gridded membrane filters are available in 0.22μm, 0.45μm, and 0.8μm pore sizes to accommodate different applications.
What diameters are available?
Available diameters include 13mm, 25mm, 28mm, 47mm, and 50mm. 47mm is the most commonly used size for standard microbiology applications.
What is the difference between white grid and black grid?
White grid membranes are used with dark/colored samples for better contrast. Black grid membranes are used with light/transparent samples like drinking water.
Are sterile gridded membrane filters available?
Yes. Hawach sterile gridded membrane filters are gamma irradiated (SAL 10⁻⁶) and individually packaged, ready to use directly from sealed packaging.
What is the absorbent pad used for?
The absorbent pad is placed under the membrane to absorb excess liquid, preventing droplet formation and ensuring clear colony counting. It is commonly used in microbiology applications.
What is the grid interval on Hawach gridded membrane filters?
The grid interval is 3×3 mm, which facilitates easy counting of colonies without compromising colony growth.
How should sterile gridded membrane filters be stored?
Store in original packaging at room temperature (15-30°C), away from direct sunlight and chemicals. Shelf life is 24 months from the date of sterilization.
Scanning Electron Microscope Picture
The quality has a guarantee
Fast & safe shipping worldwide
Contact Hawach for a Quotation
Enter your email address and our sales staff will
contact you as soon as possible.
