It is common to use ddNTPs (dideoxynucleoside triphosphates) for sequencing DNA because, when incorporated into a growing DNA polymer, the ddNTP acts as a chain terminator, allowing the researcher an opportunity to determine the last-added base to a given chain. From your knowledge of nucleotide structure and DNA synthesis, what is the most likely attribute of ddNTPs for DNA sequencing?

Question

Quizplus · Accepted Answer

Dideoxynucleotides (ddNTPs) used in DNA sequencing lack a 3' hydroxyl group on the sugar component, which prevents the addition of another nucleotide to the growing DNA strand, effectively terminating the chain. This characteristic is crucial for the Sanger sequencing method, allowing determination of the DNA sequence by identifying the terminal nucleotide of fragments of varying lengths.

It Is Common to Use DdNTPs (Dideoxynucleoside Triphosphates) for Sequencing