🔬 What is Sanger Sequencing?
Sanger sequencing, also known as the Sanger method, is a groundbreaking technique developed by Frederick Sanger in 1977 for determining the nucleotide sequence of DNA. It revolutionized molecular biology and remains a cornerstone in genetic research.
🧬 Key Principles
DNA Strand Synthesis
- Uses DNA polymerase to synthesize complementary strands.
- Incorporates chain-terminating dideoxynucleotides (ddNTPs) to stop elongation at specific positions.
Fluorescent Labeling
- ddNTPs are labeled with fluorescent tags (e.g., A - red, T - black, C - blue, G - green).
- Sequencing reactions are run in separate tubes for each nucleotide.
Electrophoresis
- Fragments are separated by size using Gel_Electrophoresis.
- The sequence is read by detecting the order of fluorescent signals.
📚 Applications
- Genetic Research: Used for sequencing genes, identifying mutations, and studying genetic diversity.
- Forensics: Critical for DNA profiling in criminal investigations.
- Medical Diagnostics: Helps detect genetic disorders and pathogens.
⚠️ Advantages & Limitations
| Pros | Cons |
|---|---|
| High accuracy (1-2% error rate) | Time-consuming and costly for large genomes |
| Reliable for short DNA sequences | Less efficient than next-generation sequencing |
👉 Expand your knowledge: Explore other DNA sequencing techniques
📌 Key Points:
- Sanger sequencing is not suitable for whole-genome projects due to its low throughput.
- It is widely used in DNA_Fragment analysis and Gel_Electrophoresis demonstrations.
💡 Tip: For larger-scale sequencing, consider next-generation sequencing tools or PCR techniques.