View source for ILLUMINA (SOLEXA) DNA SEQUENCING

Solexa DNA sequencing is a technique used sequence DNA&nbsp;one nucleotide base at a time with the use of fluorescence. 

<br>

The DNA&nbsp;fragments are&nbsp;first washed over the flow cell. Enzymes and free nucleotides are then added in order to form double stranded cross bridges and further amplification takes place. Denaturisation then occurs in order to obtain single stranded DNA fragments that are well annealed to the surface of the cell. The modified dNTP's are then added; these dNTP's include 3'blocking group instead of -OH which prevents further dNTP's pairing and different colour fluorescence depending on their base. Free dNTP's can then be washed off and a computer image is then taken which highlights the different colours. The Staudinger reaction and then hydrolysis occurs in order to get rid of fluorescence and remove the blocking group. The -OH present then allows for further addition of dNTP's in the second cycle.



Reference<references /><ref>Mardis ER (2008) Next-generation DNA sequencing methods. Annu Rev Genomics Hum Genet. 9:387-402</ref>