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  • DNA sequencing. This method of DNA sequencing is called di-deoxy sequencing. It is used to determine the order of bases (A,C,G and T) in a piece of DNA using radioactively-labelled modified nucleotides. They are then separated by electrophoresis in a polyacrylamide gel and detected on x-ray film by a process called autoradiography.
  • Illustration depicting semi-conservative DNA replication. A DNA double helix prior to replication is shown in the top left of the image. The sugar phosphate backbone and nucleotide bases are visible. Complementary base pairing of adenine with thymine (blue with green) and guanine with cytosine (red with yellow) is shown. During replication, a length of the double helix temporarily unwinds and separates into two strands. Free nucleotides bind by complementary base pairing to the recently exposed nucleotides on each strand which act as a template. Two new double helices are formed, each containing one original generation and one new generation strand of DNA. The sequence of base pairs in each double helix is identical to the original.
  • Shadow of a DNA double helix on sequencing output
  • DNA double helix and sequencing output
  • DNA sequencing autoradiograph showing the researcher's annotations.
  • DNA double helix and sequencing output
  • DNA double helix and sequencing output
  • DNA double helix and sequencing output
  • DNA double helix and sequencing output