DNA sequencing Flashcards
(16 cards)
What is DNA sequencing?
Process of determining exact sequence of nucleotides within DNA molecule
Who invented the process of genetic sequencing and how?
Frederick Sanger
sequencing nucleic acids from viruses and bacteria
radioactive labelling of bases and process called gel electrophoresis was used to determine sequence
What improvements have been made to the Sanger method?
- substitution of radioactive labels with fluorescent tags for safety and efficiency
- enhancements in scaling up and automation to process more samples at once
- introduction of capillary sequencing key method used in Human Genome Project
Outline the process of DNA sequencing?
1) DNA mixed with primers, DNA polymerase, normal nucleotide bases, and ‘terminator’ bases
2) double-stranded DNA split into single strands and copied multiple times
3) DNA polymerase adds nucleotides to single-stranded template to start rebuilding new DNA strands
4) when terminator base added DNA synthesis stops tagging each with unique fluorescent colour
5) produces DNA fragments of all possible lengths
6) DNA fragments separated by length e.g using capillary sequencing or gel electrophoresis
7) laser detects fluorescent colours of terminator bases in each fragment determining sequence order
8) with every potential base marked computer software analyses fragments reconstructing original DNA sequence
How are genomes reassembled after DNA sequencing?
Computers by comparing and overlapping DNA fragments
What is the new method of DNA sequencing?
Refers to automated high-throughput technologies that revolutionised DNA sequencing
What have the new DNA sequencing technologies facilitated?
Massively parallel sequencing = allows simultaneous sequencing of millions of DNA fragments
Exponentially increased speed = e.g bacterial genome now sequenced in less than 24 hours
Reduced costs = made it possible to sequence genomes of more organisms
What are the key fields in sequencing biological data?
Bioinformatics = developing software, computing tools, and mathematical models to collect, store, and analyse biological datasets genomes
Computational biology = uses bioinformatics tools and biological data to model biological systems and processes
Genomics = applies DNA sequencing and computational biology to study genomes of organisms
What are the benefits of sequencing pathogen genomes?
- identify sources and transmission routes of diseases
- detecting antibiotic-resistant strains
- develop new treatments and vaccines by identifying potential drug targets
- monitoring disease outbreaks
What is DNA barcoding?
Involves comparing DNA sequence of unidentified organism to database of standard ‘barcode’ sequences for known species
What does DNA barcoding allow?
Researchers to find similarities between new DNA sequences and those already in databases
indicates common ancestry and allows scientists to build evolutionary trees with greater accuracy
What are the advantages of DNA barcoding?
- fast and affordable sequencing
- classification of new species
- updating of classifications
- estimating evolutionary divergence times based on predictable DNA mutation rates to construct evolutionary trees
What is genomics?
Study of genomes using DNA sequencing and computational biology to analyse data e.g base pairs in DNA, protein structures, and gene regulation
What is proteomics?
Examines complete set of proteins produced by genome (proteome) including their structure and function
What is synthetic biology?
Design and construction of new biological parts, pathways, and organisms, or re-engineering of existing natural systems
What are potential applications of synthetic biology?
- synthesising functional genes to replace faulty ones treating genetic disorders
- utilising microorganisms and biological systems to produce drugs in efficient and cost-effective manner
- constructing fully artificial genomes
