Question

Transfer of DNA strands from agarose gel to nylon membrane is known as:

• A. Southern blotting
• B. Northern blotting
• C. Western blotting
• D. Eastern blotting

Hint:

Remember the biological matching for blotting:
Southern = DNA
Northern = RNA
Western = Protein

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
The question asks for the specific molecular biology technique used to transfer separated DNA fragments from an electrophoresis gel to a solid-phase membrane support.

Step 2: Key Concept and Approach:
The transfer of biological macromolecules from gel matrices to membranes is called blotting.
Different types of macromolecules are identified using specific blotting methods named after distinct biological molecules.
We must identify the method specifically designated for DNA transfer.

Step 3: Detailed Explanation:

• Southern Blotting: This procedure was designed by Edwin Southern in 1975.
It is used to transfer DNA fragments from an agarose gel to a nitrocellulose or nylon membrane, where they are subsequently detected using complementary probes.
Therefore, this option is correct.

• Northern Blotting: This is an adaptation of Southern blotting used to detect RNA molecules.

• Western Blotting: This is used to transfer and identify proteins separated by SDS-PAGE using antibody-antigen interactions.

• Eastern Blotting: This technique is used to detect post-translational modifications of proteins, such as lipids or carbohydrate moieties.


Step 4: Final Answer:
The transfer of DNA strands from agarose gel to a nylon membrane is Southern blotting, which corresponds to Option (A).