In the Sanger sequencing method,the use of dideoxy adenosine triphosphate stops nucleotide polymerization opposite:
A)A's in the template strand.
B)T's in the template strand.
C)G's in the template strand.
D)C's in the template strand.
E)any base selected randomly in the template strand.

Question

Quizplus · Accepted Answer

In the Sanger sequencing method, dideoxy nucleotides (ddNTPs) are incorporated into the growing DNA chain, which terminate the chain extension. Specifically, dideoxyadenosine triphosphate (ddATP) will stop nucleotide polymerization opposite of T's in the template strand. This is because the ddATP lacks a 3'-OH group, which is necessary for the formation of a phosphodiester bond to the next incoming nucleotide. As a result, the incorporation of a ddATP will halt the elongation of the DNA chain. The sequencing reaction is performed with a small amount of ddATP mixed in with regular dNTPs, allowing for chain termination at a random position along the template strand, resulting in the synthesis of a series of DNA fragments of varying lengths.

In the Sanger Sequencing Method,the Use of Dideoxy Adenosine Triphosphate