The main difference between nitrocellulose and nylon membrane is that the nitrocellulose membrane has a high affinity for protein binding whereas the nylon membrane has a high affinity for nucleic acid binding. Furthermore, hydrophobic and electrostatic interactions bind macromolecules to the nitrocellulose membranes while ionic, hydrophobic, and electrostatic interactions bind macromolecules to the nylon membranes
Nitrocellulose and nylon membrane are two types of membranes to which the macromolecules are transferred from the gel. However, nitrocellulose membranes can be used to bind DNA and RNA as well.
Key Areas Covered
1. What is a Nitrocellulose Membrane
– Definition, Structure, Mechanism of Binding, Advantages
2. What is a Nylon Membrane
– Definition, Structure, Mechanism of Binding, Advantages
3. What are the Similarities Between Nitrocellulose and Nylon Membrane
– Outline of Common Features
4. What is the Difference Between Nitrocellulose and Nylon Membrane
– Comparison of Key Differences
Key Terms
Affinity, Biodyne A, Biodyne B, Nitrocellulose, Nucleic Acids, Nylon, Pore Size, Proteins
What is a Nitrocellulose Membrane
Nitrocellulose membrane is a common matrix used in Western blotting due to the high protein-binding affinity. However, it can be used to detect nucleic acids apart from immobilized proteins and glycoproteins. The immobilization of the macromolecules mainly occurs through hydrophobic interactions. Hydrogen bonds are also formed between the nitro groups of the membrane and the amino acid side chains of the proteins. Protein immobilization will be high in the high salt and low methanol concentrations.
Figure 1: Principle of Blot
Nitrocellulose membranes are available in 100% pure forms of nitrocellulose with a high surface area, which is uniform. The available pre-sizes are 0.2 μm and 0.45 μm. The small pore size is better for the binding with small proteins (<14 kDa). The binding and retaining capacity of proteins is 80-250 μg/cm2. The pre-assembled membranes are ready to use. One of the main advantages of nitrocellulose membranes is its very low background as it can be easily blocked. The supported nitrocellulose membranes can be stripped and reprobed.
What is a Nylon Membrane
Nylon membrane is a widely used matrix for the binding of nucleic acids. Nylon membranes are mechanically strong than nitrocellulose membranes. The two main types of nylon membranes used in blotting are Biodyne A and Biodyne B. The pore size of both types are 0.45 μm. They are resistant to heat and solvents. Also, they will not shrink, crack or tear. Both give a low background than nitrocellulose membranes.
Figure 2: Southern Blot Membrane
- Biodyne A is made up of unmodified nylon 66. High sensitivity and excellent resolution are the benefits of Biodyne A. Since Biodyne A contains both positive and negative charges, it can be used to bind many types of macromolecules.
- Biodyne B is made up of positively-charged nylon 66. Therefore, it has an excellent binding capacity for negatively-charged nucleic acids such as DNA and RNA.
Similarities Between Nitrocellulose and Nylon Membrane
- Nitrocellulose and Nylon membranes are two types of membranes used to transfer macromolecules from the gel in blotting techniques.
- They allow the detection of macromolecules on the membrane.
- Both types of membranes can be used to transfer nucleic acids.
- They can be stripped and reprobed.
Difference Between Nitrocellulose and Nylon Membrane
Definition
Nitrocellulose membrane refers to a sticky membrane used for immobilizing nucleic acids and proteins in blotting while nylon membrane refers to a type of membrane with high strength and heat resistance used to immobilize macromolecules.
Made up of
Nitrocellulose membranes are made up of nitrated cellulose while nylon membranes are made up of unmodified or positively charged Biodyne A and Biodyne B nylon.
Pore Size
The pore sizes of nitrocellulose membranes are 0.2 μm and 0.45 μm while the pore size of the nylon membranes is 0.45 μm.
Strength
Nitrocellulose membranes are brittle and thus not reusable while nylon membranes are mechanically strong.
Transferring Method
Electrophoretic transfer is mainly used in the transfer of proteins onto the nitrocellulose membranes while capillary transfer is the common practice with nylon membranes.
Affinity
Nitrocellulose membranes have a high affinity to protein while nylon membranes have high affinity to nucleic acids. Nitrocellulose membranes can also be used for nucleic acids.
Blotting
Nitrocellulose membranes are better for Western blotting while nylon membranes are better for Southern and Northern Blotting.
Binding Interactions
Hydrophobic and electrostatic interactions bind macromolecules to the nitrocellulose membranes while ionic, hydrophobic, and electrostatic interactions bind macromolecules to the nylon membranes.
Protein Binding Capacity
The protein binding capacity of nitrocellulose membrane is 80-250 μg/cm2 while the protein binding capacity of nylon membrane is 150-200 μg/cm2.
Conclusion
Nitrocellulose membrane is a brittle membrane mainly used to immobilize protein in Western blotting while nylon membrane is a strong membrane mainly used to immobilize nucleic acids. The nitrocellulose membranes bind molecules through hydrophobic interactions while the nylon membranes bind molecules through electrostatic interactions. Therefore, the main difference between nitrocellulose and nylon membrane is the affinity.
Reference:
1. “Nitrocellulose Membranes for Western Blotting | Thermo Fisher Scientific – LK.” Thermo Fisher Scientific, Thermo Fisher Scientific, Available Here
2. “Biodyne A Nylon Membrane, 0.45 m, 8 Cm x 12 Cm.” Thermo Fisher Scientific, Thermo Fisher Scientific, Available Here
3. “Biodyne B Nylon Membrane, 0.45 m, 8 Cm x 12 Cm.” Thermo Fisher Scientific, Thermo Fisher Scientific, Available Here
Image Courtesy:
1. “Blot biology” By Gbdivers – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “Southern blot membrane” By Bojan Žunar – Own work (CC BY-SA 4.0) via Commons Wikimedia
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