Single-molecule real-time sequencing

Definition

Single-molecule real-time sequencing (SMRT sequencing) is a revolutionary DNA sequencing technology that allows for the direct observation of individual DNA molecules as they are being sequenced. This method utilizes the unique properties of DNA polymerases to incorporate labeled nucleotides and enables real-time monitoring of nucleotide incorporation, which improves both the speed and accuracy of sequencing while providing longer read lengths compared to traditional methods.

5 Must Know Facts For Your Next Test

1. SMRT sequencing allows for the observation of individual DNA molecules, eliminating the need for amplification which can introduce errors.
2. The technology utilizes specially labeled nucleotides that emit fluorescent signals when incorporated by the DNA polymerase, allowing for real-time tracking.
3. One of the significant advantages of SMRT sequencing is its ability to generate long read lengths, often exceeding 10,000 base pairs, which aids in resolving complex genomic regions.
4. SMRT sequencing is particularly useful for applications such as de novo genome assembly, where understanding repetitive regions is essential.
5. This technology has been instrumental in advancing fields like genomics and metagenomics, providing insights into genetic diversity and evolutionary biology.

Review Questions

• How does single-molecule real-time sequencing differ from traditional DNA sequencing methods in terms of accuracy and read length?
  • Single-molecule real-time sequencing differs from traditional methods primarily in its ability to sequence individual DNA molecules directly without amplification. This direct observation reduces errors typically introduced during amplification. Additionally, SMRT sequencing provides significantly longer read lengths, often over 10,000 base pairs, enabling more accurate assembly of complex genomes compared to shorter reads from traditional methods.
• What role do labeled nucleotides play in the process of single-molecule real-time sequencing?
  • In single-molecule real-time sequencing, labeled nucleotides are crucial because they allow for real-time detection of nucleotide incorporation as DNA is synthesized. Each time a nucleotide is added to the growing DNA strand by the DNA polymerase, it emits a specific fluorescent signal corresponding to that nucleotide. This immediate feedback loop not only provides data on the sequence being synthesized but also enhances the overall accuracy and efficiency of the sequencing process.
• Evaluate the impact of single-molecule real-time sequencing on genomic research and its potential future applications in personalized medicine.
  • Single-molecule real-time sequencing has had a profound impact on genomic research due to its high accuracy and ability to produce long reads, making it easier to assemble complex genomes and analyze genetic variations. As researchers continue to explore its applications, such as identifying rare mutations and understanding complex diseases, its integration into personalized medicine could revolutionize how treatments are tailored to individuals based on their unique genetic profiles. The ongoing advancements in this technology suggest that it will play a central role in future genomic studies and clinical applications.

Related terms

DNA Polymerase: An enzyme responsible for synthesizing new DNA strands by adding nucleotides to a growing chain during DNA replication.

Sequencing By Synthesis: A method of DNA sequencing that determines the sequence of nucleotides by synthesizing a complementary strand and detecting incorporated nucleotides in real-time.

Read Length: The length of the DNA sequence that can be read in a single sequencing run, typically measured in base pairs, which is critical for accurately assembling genomes.