DNA Test Methods - DNA Sanger Sequencing

View the full Interactive Tutorial at:
http://www.phgfoundation.org/tutorials/dna/5.html

Once a piece of DNA has been amplified, it can be sequenced. In this process, four reaction mixtures are set up, each one including: 1. DNA to be sequenced
2. DNA polymerase
3. A supply of nucleotides (A, C, G and T)
4. A small amount of a labelled chain-terminating variant of one of the four nucleotides.

The enzyme DNA polymerase incorporates a chain-terminating variant at random, eventually ending the chain at every possible nucleotide position over a few hundred bases.

The products of the reaction mixtures are run on an electrophoresis gel, where the sequence can be deduced by reading from the smallest to the largest piece.

If different fluorescent labels are used for the variant bases, sequencing can all be done in one single reaction, the bands can be detected and the sequence read out automatically. The entire process of DNA sample preparation and sequencing is now highly automated, a development that has been essential for the timely and cost-effective completion of the human genome project.

Category:

Science & Technology

Tags:

• phgfoundation
• interactive
• tutorials
• dna
• test
• methods

[Spectre2904]

Why is youtube more useful than actually going to class arghhhhhhhh.

[harboee]

slower please.. im retarded (and have exam tmw :( )

[AgentMultiSuccess]

omagosh, reading the textbook i was like wtf...but seeing this, it's soo easy and straightforward! XD

[iLOVENATURE2011]

Amazing... thank you for uploading...

[jay8950]

you forgot about the primers, good video though thanks.

[polyinmypocket]

Thank you!

[vollexus]

excellent! Thanks so much I get it now :)

[Brudy15]

Grande sei un figo

[shardhanamorgan]

I am in love with the accent. seriously...

[Sassylicious16]

@13aird bio

[dawncoming]

@harboee me too. it's kinda fast. have to watch several times to get the essence of it.

[lassiechild]

The is also a primer added, a dideoxynucleotide base (A,T,G,C, are each in separate tubes), DNA polymerase, and free dNTP's (some fluorescently labelled for visualisation of the bands under x-ray film.