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What is the difference between PVDF membrane 0.22 and 0.45 (PVDF membrane precautions)
PVDF membrane (polyvinylidene fluoride membrane) is widely used in Western Blot experiments for protein transfer printing, but its essence is a hydrophobic polymer that requires pre-treatment activation before use to make it easier to use in aqueous buffer solutions. PVDF membranes have different pore sizes, which can affect their performance and applicability in filtration and separation applications.
PVDF pore sizes vary
0.22 μ m PVDF membrane is suitable for intercepting smaller molecules, such as protein molecules smaller than 20kD. This type of membrane has a smaller pore size and can effectively filter out smaller particles and bacteria.
The 0.45 μ m PVDF membrane is suitable for larger molecules of proteins and nucleic acids, as well as proteins larger than 20kD. This type of membrane has a larger pore size, making it more suitable for situations where larger particles need to be retained.
PVDF operating pressure and flux are different
The membrane pore size of 0.22 μ m is relatively small and typically requires higher operating pressure to maintain the same flux, which may result in higher operating resistance.
The membrane pore size of 0.45 μ m is larger, allowing for greater flux and typically requiring lower operating pressure, thus having lower operating resistance.
PVDF protein transfer and resolution are different
The 0.22 μ m membrane is particularly suitable for protein transfer with a molecular weight of less than 20kDa due to its small pore size and high binding capacity. Having higher transfer resolution, it is suitable for detecting multiple bands of similar protein size or conducting fine protein quantitative analysis.
A 0.45 μ m membrane is more suitable for protein transfer with a molecular weight greater than 20kDa. The larger pore size reduces clogging on the membrane, resulting in relatively lower resolution, but may be more effective in transferring high molecular weight proteins.
PVDF has different application ranges
0.22 μ m PVDF membrane is suitable for applications with high microbial barrier properties, such as the medical industry, biopharmaceuticals, laboratories, and drinking water treatment.
0.45 μ m PVDF membrane is suitable for particle removal, pre filtration, and some microbial filtration applications, such as food and beverage processing, wastewater treatment, and laboratory pre filtration.
Precautions for using PVDF membrane
✔ Methanol activation
Soak in methanol before use. Methanol can activate the surface of PVDF membrane, increase its hydrophobicity, and thus enhance its protein binding ability.
✔ Avoid dryness
After activating the film, during the film transfer process, and after the film transfer is completed, it is necessary to quickly transfer the film between liquids to avoid drying the film in the air, which may affect subsequent exposure.
✔ Avoid direct contact
Direct contact with the membrane surface by hand should be avoided to prevent contamination by oil and protein, which can affect membrane transfer efficiency and produce background stains. The membrane should be operated with tweezers throughout the process to reduce contamination and physical damage.
✔ Drain all bubbles
During electrotransfer printing, it is necessary to ensure that there are no bubbles between the gel and PVDF film, because bubbles will affect the uniform transfer of protein.