Sanger DNA sequencing method

Definition

Sanger DNA sequencing is a method used to determine the nucleotide sequence of DNA. It involves chain termination with dideoxynucleotides during DNA synthesis.

5 Must Know Facts For Your Next Test

1. Developed by Frederick Sanger in 1977, it was the first widely used DNA sequencing method.
2. The method uses labeled dideoxynucleotides (ddNTPs) to terminate DNA strand elongation at specific nucleotides.
3. It requires a single-stranded DNA template, a primer, DNA polymerase, normal deoxynucleotides (dNTPs), and modified ddNTPs.
4. The resulting fragments are separated by size using gel electrophoresis or capillary electrophoresis to read the sequence.
5. Sanger sequencing has been largely replaced by next-generation sequencing (NGS) for large-scale genomic projects but is still used for smaller-scale applications.

Review Questions

• What role do dideoxynucleotides (ddNTPs) play in Sanger sequencing?
• How are the DNA fragments generated by Sanger sequencing separated and analyzed?
• Why is Sanger sequencing considered less practical than next-generation sequencing for large genomic projects?

Related terms

Next-Generation Sequencing (NGS): Advanced methods that allow rapid and high-throughput determination of nucleotide sequences.

Dideoxynucleotide (ddNTP): Modified nucleotide that lacks a hydroxyl group at the 3' carbon, causing termination of DNA strand elongation.

DNA Polymerase: An enzyme that synthesizes new strands of DNA complementary to the template strand during replication or PCR.