Hawach to Talk About the Applications and Differences Filter Membrane

Based on membrane filtration principle, Hawach provides different types of microporous membranes. Filter membranes are mainly used for the filtration of the mobile phase and samples in chromatographic analysis. PVDF membrane protein binding is widely used in gravimetric analysis, microanalysis, colloid separation, and sterility tests. Filter membranes of different materials have different characteristics and applications. The description and application of the PES VS PVDF filter, the difference between PVDF and nylon filters membrane, and the NC membrane are as follows.

1. PES filter membranes

Polyethersulfone (PES for short) is prepared by the condensation of 4,4′-bissulfonyl chloride diphenyl ether with diphenyl ether, catalyzed by anhydrous ferric chloride. For the heat resistance ability, it is between polysulfone and polyarylsulfone. It has excellent aging resistance and can be used for up to 20 years at 180°C. It has good flame resistance and does not emit smoke even if it burns, and it also features good creep resistance.

Applications: For general alkali, aliphatic hydrocarbons, oils, and alcohols, the PES filter membrane’s performance is stable and suitable for physical and chemical sterilization, such as high-pressure steam, gamma radiation, and ethylene oxide sterilization, with a high bubble point and excellent membrane integrity. The PES filter membrane material has a very low protein adsorption rate, which can ensure the stability of the components of the filtered drug solution, and is suitable for disposable precision filtration infusion sets and anesthesia drug solution filters. PES is often used in the manufacture of hemodialyzers, blood concentrators, artificial lungs, etc., due to its excellent mechanical properties, stable wetting strength, and blood compatibility.

PES filter vs PVDF. PES vs PVDF filter. PVDF filter membranes have higher oxidant resistance and mechanical strength than PES filters.

2. PVDF filter membrane (Polyvinylidene fluoride membrane)
PVDF membrane, or polyvinylidene fluoride membrane, is a kind of solid-phase support commonly used in Western blotting. The PVDF membrane is hydrophobic, and the pore size of the membrane can be large or small. As the pore size of the membrane continues to decrease, the membrane is more firmly bound to low molecular weight proteins.

For proteins larger than 20000, a 0.45 μm membrane is used, and for proteins smaller than 20000, a 0.2 μm membrane is used. The use of the PVDF membrane requires pretreatment. The purpose of the methanol treatment is to activate the positively charged groups on the membrane, making it easier to bind to negatively charged proteins. With high mechanical strength, the PVDF membrane is an ideal solid support material in the imprinting method. In addition, PVDF vs PES. PVDF filter membranes have a slower flow rate than PES filter membranes.

Applications: Hydrophobic polyvinylidene fluoride membrane is mainly used in gas and vapor filtration, and high-temperature liquid filtration; hydrophilic polyvinylidene fluoride membrane is mainly used in tissue culture medium, additives, and other sterilization filtration solvents, and purification filtration of chemical raw materials, aseptic processing of reagents, filtration of high-temperature liquids, etc. PES vs PVDF. If your application involves exposure to higher temperatures, PES might be more suitable than PVDF due to its better temperature stability.

PVDF vs PES

Polyvinylidene fluoride (PVDF) and polyethersulfone (PES) are both synthetic polymers used in various applications, including filtration membranes. PVDF offers excellent chemical resistance and is often used in harsh environments. PES, on the other hand, has high thermal stability and is resistant to hydrolysis. When choosing between PVDF and PES, PVDF vs PES, consider factors such as chemical compatibility, temperature resistance, and intended applications. PVDF may be preferred for its chemical resistance, while PES may be chosen for its stability at elevated temperatures. Ultimately, the choice depends on the specific requirements of the intended use.

In summary, PVDF membranes are preferred for applications requiring excellent chemical resistance and low protein binding, such as protein analysis and filtration of aggressive solvents. On the other hand, PES membranes are chosen for applications demanding high flow rates, low protein binding, and compatibility with aqueous solutions, such as sterile filtration and general laboratory filtration.

Click here to learn more about “PVDF vs PTFE” and “PVDF Membrane Filter Media Introduction“.

3. Nylon membrane
Nylon membrane is a synthetic, long-chain polyamide membrane, which has a strong binding ability to nucleic acid and protein and can replace nitrocellulose membranes for molecular imprinting and hybridization experiments. Nylon membrane features good temperature resistance, which can withstand 121℃ saturated steam hot-press sterilization for 30min, and the maximum working temperature is 60℃; also, it has good chemical stability, which can withstand dilute acid, dilute alkali, various organic and inorganic compounds such as alcohols, esters, oils, hydrocarbons, halogenated hydrocarbons, and organic oxides. Difference between PVDF and nylon filters. Nylon membranes have higher protein-binding properties compared to PVDF membranes.

Applications: Electronic, microelectronics, semiconductor industry, water filtration, tissue culture medium filtration, liquid medicine filtration, beverage filtration, high-purity chemical filtration, filtration of aqueous solutions, and organic mobile phases. It has the widest applications, such as aqueous solution and organic mobile phase filtration, filtration of beverages and chemical liquids, filtration of tissue culture medium, and so on.

Click here to learn “Features and Applications of Nylon Filter Membrane“.

4. NC membrane
Nitrocellulose filter membrane (NC membrane for short) is used in Northern Blot, Southern Blot, and Western Blot. Hybridization techniques include solid-phase hybridization and liquid-phase hybridization. Solid-phase hybridization technology is currently more commonly used.

The nucleic acid to be tested is bound to a certain solid-phase support and then hybridized with the labeled probe in the liquid phase. Nitrocellulose membranes are commonly used for solid supports.

Difference between Nylon and PVDF filter membranes and the NC filter membrane

Nylon vs PVDF filter, NC filter membrane. The difference between nylon and PVDF filter membranes is that the Nylon membrane is an ideal nucleic acid solid support, and there are many types. Nitrocellulose membrane is currently the most widely used solid support with the lowest price; the PVDF membrane is somewhere in between.

1. In terms of the Material Composition of the Nylon membrane, PVDF membrane, and NC membrane

• Nylon: Nylon filters are made from a synthetic polymer known as polyamide. They are hydrophilic, meaning they have an affinity for water and other polar solvents.
• PVDF: PVDF filters are composed of a synthetic fluoropolymer called polyvinylidene fluoride. PVDF membranes are hydrophobic, repelling water and attracting nonpolar solvents.
• NC: NC filters are made from a naturally derived polymer called nitrocellulose. Nitrocellulose is also hydrophilic and has a good protein-binding capacity.
• PES: PES filters are made from polyethersulfone, a synthetic polymer known for its high strength and chemical stability. PES membranes are hydrophilic and are commonly used in applications involving water-based solutions.

2. In terms of the Chemical Compatibility of the Nylon membrane, PVDF membrane, and NC membrane

• Nylon: Nylon filters are chemically compatible with a wide range of solvents, acids, and bases. They are suitable for applications involving organic solvents and aqueous solutions.
• PVDF: PVDF filters have excellent chemical compatibility with strong acids, bases, and organic solvents. They are resistant to many chemicals and are commonly used in aggressive chemical filtration.
• NC: NC filters have limited chemical compatibility and are susceptible to degradation in some organic solvents, strong acids, and bases. They are primarily used for applications involving protein or nucleic acid analysis.
• PES: PES filters exhibit excellent chemical resistance, especially to organic solvents and high-temperature aqueous solutions. They are stable in a broad range of chemicals, making them ideal for biofiltration and water purification.

3. In terms of the Pore Size and Filtration Efficiency of the Nylon membrane, PVDF membrane, and NC membrane

• Nylon: Nylon filters are available in a wide range of pore sizes, typically ranging from 0.1 μm to 10 μm. They offer high flow rates and good particle retention.
• PVDF: PVDF filters are also available in various pore sizes, ranging from 0.1 μm to 5 μm. They offer high flow rates and have excellent particle retention properties.
• NC: NC filters are commonly used in protein analysis and are available in different pore sizes, typically ranging from 0.1 μm to 0.45 μm. They provide good protein binding and retention.
• PES: PES filters typically range from 0.1 μm to 0.45 μm in pore size. They are known for their high filtration efficiency and are commonly used in applications requiring precise filtration of aqueous solutions.

4. In terms of the Toughness of the Nylon membrane, PVDF membrane, and NC membrane

• The nylon membrane is stronger.
• PVDF membrane is stronger.
• NC membrane is more brittle and easily broken.
• PES: PES membranes are tough and exhibit good mechanical strength, with better tear resistance than NC membranes, but are slightly less durable than PVDF membranes.

5. In terms of the Binding Capacity of the Nylon membrane, PVDF membrane, and NC membrane

Nylon vs PVDF filter.

• Nylon membranes can bind DNA and RNA up to 480-600μg / cm2 and can bind nucleic acid fragments as short as 10bp.
• PVDF membrane can bind DNA and RNA up to 125-300μg / cm2.
• NC membranes can bind DNA and RNA up to 80-100μg / cm2. The 200bp nucleic acid fragment has a weak binding ability.
• PES: PES membranes have a lower protein binding capacity compared to PVDF and NC membranes. They are typically used in applications where minimal protein binding is desirable, such as the filtration of biological samples without protein loss.

6. In terms of the Temperature Adaptability of the Nylon membrane, PVDF membrane, and NC membrane

• After the nylon membrane is baked or irradiated with ultraviolet rays, some of the pyrimidine bases in the nucleic acid can be combined with the positive charge on the membrane.
• PVDF membrane is firmly bonded and resistant to high temperatures and is particularly suitable for Western blotting.
• Nitrocellulose membrane relies on hydrophobic interaction to bind DNA, and the binding is not strong.
• PES: PES membranes can withstand a broad range of temperatures, making them suitable for both low and high-temperature applications. They maintain their integrity and performance at elevated temperatures compared to other hydrophilic membranes.

7. In terms of the Repeatability of the Nylon membrane, PVDF membrane, and NC membrane

(1) The nylon membrane can be used repeatedly for molecular hybridization. After hybridization, the probe molecules can be eluted by alkali denaturation; the PVDF membrane can be reused, but the nitrocellulose membrane cannot be reused.

(2) Compared with nitrocellulose membranes, PVDF membranes have superior performance in protein retention, mechanical strength, and chemical compatibility. The typical binding capacity of commercially available nitrocellulose membrane is 80-100μg / cm2, while the binding capacity of the PVDF membrane is 100-200μg / cm2 (and the binding strength of PVDF is 6 times stronger than nitrocellulose membrane!).

But the biggest advantage of PVDF membranes is not only this: better mechanical strength and chemical resistance make PVDF membranes ideal for various staining applications and multiple immunoassays, and a single lane copy of the gel can be used for multiple purposes. In particular, it is necessary to do N-terminal protein sequencing.

Under fairly “severe” cleaning conditions, the PVDF membrane remains intact when the nylon or nitrocellulose membrane has been degraded, so PVDF is also the best choice for protein sequencing. But it is not suitable for fluorescence. Particular attention should be paid to PVDF membranes that require 100% methanol pretreatment (not more than 15 seconds) and then equilibrated with buffer before they can be used.

(3) Since some detergents will replace the protein bound on the NC membrane, use a milder Tween 20 when blocking, and the concentration should not exceed 0.3%. Generally speaking, the purer the NC membrane, the higher its protein binding capacity, so it is a consideration to increase the sensitivity and resolution of WB and improve the purity of the membrane used. If the NC membrane is mixed with some cellulose acetate, which has been mentioned before, it will affect the protein binding.

The use of the NC membrane is also very simple. For example, no formaldehyde pretreatment is required, as long as it is infiltrated on the surface of non-ionized water to expel the air bubbles in the membrane, and then equilibrated in electrophoresis buffer for a few minutes; the NC membrane is easy to close, and neither are particularly strict cleaning conditions required. The protein transferred to the NC membrane can be stored stably for a long time under appropriate conditions, but it should be noted that the pure nitrocellulose membrane is relatively brittle and easy to roll, and care should be taken during use.

When choosing a nitrocellulose membrane, it is necessary to choose a suitable pore size. Generally, large molecular proteins above 20 kDa use a membrane with a pore size of 0.45 μm. If the membrane is less than 20 kDa, it is recommended to choose 0.2 μm. Also, note that the selection of a pure NC membrane mixed with cellulose acetate (CM), containing the NC membrane, will reduce the binding force.

(4) PES membranes can be used multiple times, especially in filtration applications where high purity and low protein binding are critical.

8. In terms of the Applications of the Nylon membrane, PVDF membrane, and NC membrane

• Nylon: Nylon filters are versatile and are commonly used in a wide range of applications, including HPLC sample preparation, sterile filtration of aqueous solutions, and filtration of solvents and chemicals.
• PVDF: PVDF filters are frequently used in applications requiring chemical resistance, such as aggressive solvent filtration, air and gas filtration, and filtration of strong acids and bases.
• NC: NC filters are primarily used in applications such as protein analysis, Western blotting, dot blot assays, and nucleic acid analysis.

• PES: PES filters are widely used in biological and pharmaceutical applications, especially in the filtration of aqueous solutions, protein solutions, and biological media. They are ideal for cell culture applications, protein purification, and sterilization processes.

Key Differences and Considerations:

• PES and PVDF are great choices for aqueous filtration and biological processes, where protein binding and chemical resistance are key factors. PES is especially useful for aqueous samples, while PVDF can be modified for both aqueous and organic solvent filtration.
• Nylon is a more cost-effective option, ideal for general filtration applications, but with lower chemical resistance than PVDF and PTFE.
• PTFE is the top choice for organic solvent filtration and gas filtration thanks to its unmatched chemical resistance and thermal stability.
• NC membranes are suitable for general laboratory use, especially when a low-cost option is needed for the filtration of aqueous solutions or moderately aggressive solvents.

According to the application and the difference between the nylon membrane, PVDF membrane, and NC membrane, and the sample to be filtered, select the appropriate filter membrane. Hawach specializes in providing different kinds of filter membranes to meet various lab requirements. Welcome to visit the membrane manufacturer HAWACH for more details.

After we know the applications and differences of filter membranes, maybe we also should see the “Cleaning Methods of Membrane Filter“, “Membrane Material and Performance Characteristics of Filter Membrane“, and “Membrane Filtration Applications“.