Question

Which of the following DNA sequencing method uses dideoxyadenosine triphosphate?

• A. Maxam and Gilbert
• B. Sanger
• C. Chemical
• D. Direct PCR sequencing

Hint:

Remember that Sanger sequencing is synonymous with "dideoxy sequencing" or "chain-termination sequencing" due to its reliance on ddNTPs ($\text{ddATP}$, $\text{ddGTP}$, $\text{ddCTP}$, $\text{ddTTP}$).

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
DNA sequencing methods identify the precise order of nucleotides within a DNA molecule.
The chain-termination method relies on modified nucleotides to selectively halt DNA synthesis.

Step 2: Detailed Explanation:
- The Sanger sequencing method (dideoxy sequencing) utilizes dideoxynucleotide triphosphates (ddNTPs), such as dideoxyadenosine triphosphate (ddATP).
- These ddNTPs lack the 3'-OH group required for the formation of a phosphodiester bond with the next incoming nucleotide.
- When DNA polymerase incorporates a ddATP into the growing strand during replication, synthesis is terminated immediately.
- Running these terminated fragments on a gel allows the determination of the position of adenine bases in the template strand.

Step 3: Final Answer:
The sequencing method that utilizes dideoxyadenosine triphosphate is the Sanger method.