Cytiva's sterile Whatman MicroPlus-21 cellulose nitrate membrane filters are for microbiological quality control. The STL version is compatible with Membrane-Butler and other membrane filter dispensers.

• All MicroPlus-21 membrane filters are white with a high-contrast black grid (3.1 mm)
• Designed specifically for microbiological QC
• High mechanical strength and flow rate
• Tested for bubble point, bacterial retention, flow rate, recovery rate, and sterility
• Individually packaged for convenience and sterility
• Type STL provided in dispenser boxes with 100 numbered membrane filters for easy removal and secure handling using Cytiva's Membrane-Butler

Cytiva's business offers a range of Whatman cellulose nitrate membrane filters, including both sterile and non-sterile options in gridded and non-gridded formats.

In microbiological QC testing, liquid is first filtered through a membrane, allowing the microorganisms to collect on the surface. The filter is then incubated on a nutrient medium, and individual colonies are evaluated via a microbial contamination test.

All Whatman brand membranes used for microbiological quality control are tested systematically in order to ensure the same high quality from batch to batch. Bacterial retention, bubble point, flow rate, recovery rate, and sterility are all tested.