2. What is DNA Sequencing?
• DNA Sequencing is finding the order of nucleotides in a fragment of DNA
• These 4 bases are cytosine, guanine, adenine, or thymine.
3. History of DNA Sequencing
• This method was founded in 1975 by Frederick Sanger
• This method was named after him and called Sanger Sequencing
4. How the Sanger Method Works
• Is similar to the process of DNA replication
• Sanger method uses non-real radioactively-labeled bases that help stop
DNA replication
• These fake nucleotides are colored corresponding to the nucleotides so
that scientists know how to read them
5. The First Step
• First, many copies of the DNA fragment are needed to be made.
• To do this, scientist use the Polymerase Chain Reaction that heats and
cools DNA to make quick copies of the fragment
6. The Next Step
• Fragments are heated again to be unwound in to single-stranded DNA
• Then a primer is added which binds to the DNA
• ddNTPs are added
7. The Final Step
• The DNA strand is run through Gel Electrophoresis which sorts the
fragments by size
8. How DNA Sequencing is helpful to
Scientists
• Used in field of functional genomics which is the study of what certain
DNA fragments codes for and what DNA fragments code proteins
Also used in field of comparative genomics which compares organisms DNA to
other organisms to find out more about the organisms history.
9. The Advantages of DNA Sequencing
• Improve health care
• Helping plants and animals to be able to resist certain diseases
• Helps in forensic science for identifying criminals
10. The Disadvantage
• The risk that the DNA sequencing may not work right and provide the
wrong DNA sequence of that fragment