The mixed cellulose ester (MCE) membrane filters has a uniform pore structure, consistent thickness, and a smoother surface, the membrane could be made with support or without support layer in roll or discs. They are optimized for use as a variety of sample media and applications–including large-volume samples and designed for quick and easy identification of surface-retained particles and decreased eye fatigue. White discs to observe changes in color; black discs that contrast microorganisms, yeast, and mold and facilitate manual counting without a counter-stain; and gridded options for both colors to accurately quantify microbial growth/colonies. Additionally, sterile membranes are available for use with critical samples.