DNA sequencing - the 454 method

Watch or download our animation on 454 machines, which are able to read one gigabase of DNA sequence in a couple of days, at a cost of $0.02 per 1000 bases.

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DNA fragments are anchored to tiny beads (one fragment for each bead), which are then put into wells on a plate. Nucleotides are washed over the wells in waves and, as they are incorporated into the new DNA strand, the intensity of the light given off is used as a measure of how many As, Ts, Cs or Gs have been incorporated.

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This animation is © The Wellcome Trust. It is freely available for private and educational use. For commercial use, please contact Wellcome Images: images@wellcome.ac.uk.