In Sanger sequencing, does each labeled DNA molecule have a fluorescently labeled dideoxyribonucleotide at its 5′ end or its 3′ end? Do the labeled nucleotides lack the 2′ or 3′ hydroxyl group?
A) 3′ end; 2′ hydroxyl group only
B) 3′ end; 3′ hydroxyl group only
C) 5′ end; 2′ hydroxyl group only
D) 5′ end; 3′ hydroxyl group only
E) 3′ end; both hydroxyl groups

Question

Quizplus · Accepted Answer

The dideoxyribonucleotides terminate the chains because they lack the 3′ hydroxyl group required for further polymerization. Additionally, all DNA nucleotides lack the 2′ hydroxyl group.

In Sanger Sequencing, Does Each Labeled DNA Molecule Have a Fluorescently