Question

Which of the following technique is suitable for identifying mRNA molecule in a sample?

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

Hint:

Northern blotting is essential for detecting and studying RNA, including mRNA, in gene expression studies.

Answer 1

The Correct Option is B

Step 1: Understanding Northern blotting.
Northern blotting is a laboratory technique used to detect specific RNA molecules among a mixture of RNA. It is typically used to identify mRNA in a sample, allowing the study of gene expression.
Step 2: Analyzing the options.
(1) Western blotting: Incorrect, Western blotting is used to detect proteins, not RNA.
(2) Northern blotting: Correct — Northern blotting is used specifically for detecting RNA, including mRNA.
(3) Southern blotting: Incorrect, Southern blotting is used to detect specific DNA sequences.
(4) Eastern blotting: Incorrect, this is not a commonly used technique in molecular biology.
Step 3: Conclusion.
The correct technique for identifying mRNA is (2) Northern blotting.

Answer 2

Each blotting technique is named for and designed to detect a specific type of biomolecule. Let's match each option to what it actually detects.

1. Western blotting: This technique is used to detect and identify specific proteins in a sample using antibodies, not RNA.
2. Northern blotting: This technique transfers RNA fragments separated by gel electrophoresis onto a membrane and uses a labeled probe to detect specific RNA sequences, including mRNA, making it the technique suited to this question.
3. Southern blotting: This technique is used to detect specific DNA sequences, not RNA.
4. Eastern blotting: This is a less standardized technique sometimes used for detecting post-translational modifications of proteins, and it is not the established method for identifying RNA.

Matching each technique to the biomolecule it targets confirms Northern blotting as the one used for mRNA.

Therefore, the correct answer is Northern blotting.