Sanger method most widely used – dideoxy DNA sequencing, method based on
DNA synthesis carried out in vitro in the presence of special, chain-terminating
dideoxyribonucleoside triphosphates
DNA polymerase is used to make partial copies
of the DNA fragment to be sequenced
DNA replication reactions performed under
conditions that ensure the new DNA strands
terminate when a give nucleotide (A,G,C,T) is
reached – reactions ultimately produce a
collection of different DNA copies that
terminate at every position in the original
DNA, and thus differ in length by a single
nucleotide
DNA copies can be separated on the basis of
their length by gel electrophoresis, and the
nucleotide sequence of the original DNA can be determined from the order of
the DNA fragments in the gel
The Process
- The reaction is carried out in
parallel with each of the
dideoxynucleotides (ie. 4 reactions
– ddAGP, ddGTP, ddCTP and ddTTP)
- The reaction products are run in
parallel on a sequencing gel and
visualised by autoradiography –
insepection of the pattern of bands allows the complete sequence to be
reconstructed
1. To determine the complete sequence of a DNA fragment, the ds DNA
denatured, one of the ssDNA strands becomes template for sequencing
2. Four different dideoxynucleoside triphosphates used in 4 separate DNA
synthesis reactions on copies of the same ssDNA template
3. Each reaction produces a set of DNA copies that terminate at different
points in the sequence
4. Products of 4 reactions separated by electrophoresis in 4 parallel lanes of a
polyacrylamide gel
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Cheesecakeextreme. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $4.39. You're not tied to anything after your purchase.