What is the primary purpose of using fluorescently labeled dideoxynucleotides (ddNTPs) in Sanger sequencing?
Show answer and explanation
Correct answer: To terminate DNA synthesis at specific bases and label the fragments
Dideoxynucleotides (ddNTPs) lack a 3'-OH group, which prevents the formation of a phosphodiester bond with the next incoming nucleotide, thereby terminating DNA strand elongation. When labeled with a fluorescent dye, they allow for the detection of the terminal base of each fragment via capillary electrophoresis.
Keep practicing
More DNA Sequencing questions
- In next-generation sequencing (NGS), what is the primary function of bridge amplification?
- A molecular pathologist identifies a homozygous deletion in the SMN1 gene using MLPA. What is the primary limitation of this technique comp…
- During Illumina sequencing-by-synthesis, what causes the specific fluorescence emission during each cycle?
- What is the role of proteinase K in the DNA extraction process prior to sequencing?
- In the context of clinical NGS, what does 'depth of coverage' refer to?
- A tumor sample shows an allele frequency of 5% for a specific KRAS mutation. Which sequencing artifact is most critical to rule out before…