Sterile, mesh membrane filters are widely used for routine microbiological quality control because of the benefits they offer. Membrane filters are ready to use, and each filter is packaged individually, providing the highest safety while saving preparation time. Each individual envelope is marked with a filter identification and a batch number.
Membrane filters are available in different pore sizes and in three different types of materials. Cellulose nitrate filters (mixed cellulose ester) contain a mixture of cellulose nitrate and cellulose acetate, a material that ensures effective retention in combination with high flow and optimal colony growth. Cellulose acetate combines high flow rate and thermal stability with very low adsorption characteristics. Different filter colors provide the best possible contrast to colonies for easy and reliable quantification and identification.