The DNA sequencing method developed by Fred Sanger forms the basis of automated "cycle" sequencing reactions today. Scaling up to sequence. In the 1980s, two key developments allowed researchers to believe that sequencing the entire genome could be possible. The first was a technique called polymerase chain reaction (PCR) that enabled many copies of DNA sequence to be quickly and accurately produced. The second, an automated method of DNA sequencing, built upon the chemistry of PCR and the sequencing process developed by Frederick Sanger in 1977.
(DNAi Location: Genome > The Project > Putting it together > Animations > Sanger sequencing)

Duration: 51 seconds

The first method of sequencing the genetic code was devised by Fred Sanger. To sequence the DNA, it must first be separated into two strands. The strand to be sequenced is copied using chemically altered bases. These altered bases cause the copying process to stop each time one particular letter is incorporated into the growing DNA chain. This process is carried out for all four bases, and then the fragments are put together like a jigsaw to reveal the sequence of the original piece of DNA.