Analysis of the working principle of microporous filtration membrane for microbial detection

Microporous filtration membranes are based on the principle of size separation and are more commonly used in the detection of pathogenic microorganisms and microbial contamination detection industries. These membranes have precise pore structures that allow liquid or gas to pass through, while effectively retaining or discarding microorganisms according to their size.

Microporous filtration membranes are composed of a network of interconnected pores that are designed to have specific dimensions, usually in the micron (μm) or nanometer (nm) range, depending on the size of the target microorganism, the pore size distribution of the filtration membrane and uniformity play a crucial role in achieving efficient filtration. When a fluid or gas sample containing microorganisms passes through the membrane, microorganisms smaller than the pore size can pass through the pores, while larger microorganisms are trapped on the surface of the membrane. Microorganisms such as bacteria, fungi, and viruses all have characteristic sizes. In the pore size of the filter membrane When designed to be smaller than the size of the target microorganisms, larger microorganisms are physically unable to pass through the pores and are intercepted on the membrane surface. This is one of the principles of microporous filtration membranes based on microbial filtration.

In addition to size exclusion, some microorganisms also interact with the membrane surface due to adhesion, because some membrane materials have surface properties that promote microbial adhesion and capture. This adsorption mechanism allows microorganisms to be retained on the filter membrane. At the same time, The interaction between filtration membrane materials and microorganisms also includes electrostatic forces, van der Waals forces, hydrogen bonds, and hydrophobic interactions. Membranes using different materials also have different interactions. Therefore, microorganisms must also be fully considered when selecting membranes. characteristics.

The selection of membrane materials is very important for pathogenic microorganism detection and microbial contamination detection. Different materials have different chemical resistance, hydrophilicity/hydrophobicity and surface charge characteristics. These characteristics will affect the capture and retention of microorganisms, so in The selection of membrane materials should be done on the premise that they are compatible with the sample matrix and downstream analysis methods. Filter membrane materials commonly used for pathogenic microorganism detection and microbial contamination detection include polycarbonate (PC), mixed cellulose ester (MCE), and polyvinylidene. Vinyl fluoride (PVDF), polyethersulfone (PES), etc.

In summary, the working principle of microporous filtration membranes used for pathogenic microorganism testing and microbial contamination detection is to selectively allow liquid or gas to pass through, while effectively retaining microorganisms based on their size and interaction with the membrane surface, but even if microbial filtration membranes Membranes can effectively capture microorganisms, but in practical applications additional steps are required to detect and analyze the captured microorganisms, such as culture, staining, or molecular techniques.