Sequencing is a high throughput technology which enables to read DNA strains. Before going through the automatic sequencing machines, fluorescent molecules are inserted into the DNA strains by the Sanger method (http://www.bio.davidson.edu/Courses/Molbio/MolStudents/spring2003/Obenrader/sanger_method_page.htm). After being exited by a laser, the detection cells of these machines capture the light produced by these molecules and the DNA sequence can then be read, base by base, by a computer.
The sequencing platform at the Station Biologique de Roscoff the Genomer reads, every day, thousands of sequences of DNA for many researchers in the station and in other laboratories in France and Europe within the network of excellence MGE.
The data obtained from this technique being raw, analysis using bioinformatics will often be necessary to put back all the sequences obtained in the correct order and do many other kinds of studies.
Sequencer
credit photograph: Stephanie Ries
This is one of the automatic sequencers of the Genomer platform at the Station Biologique de Roscoff. This is the machine that sequences the DNA strains. The samples are put in the bottom and are sucked up by the capillary tubes. The laser and detection cell are inside this machine.
Results
credit photograph: Stephanie Ries
The detection cell of the sequencer is linked to this computer. The image on the screen shows the final results of the experiment. Each coloured peak shows the passage of a fluorescent molecule in front of the detection cell. Each peak therefore corresponds to a nucleic acid or base of the DNA strain that the computer is capable to recognize thanks to the colour of the fluorescent probe attached to it. The order of these peaks corresponds to the order of the bases of the DNA sequence.
Robot making sequencing reactions
credit photograph: Stephanie Ries
This robot prepares the samples of DNA before putting them into the automatic sequencer. This is where the fluorescent probes and the ddNTPs are added to the solutions and where the sequencing reaction will be done (see text).
