454 DNA Sequencing, based on sequencing-by-synthesis, is the power behind the performance of the Genome Sequencing FLX System454 Sequencing, based on sequencing-by-synthesis, is the power behind the performance of the Genome Sequencing FLX System. Nucleotides are flowed sequentially in a fixed order across the PicoTiterPlate device during a sequencing run. During the nucleotide flow, hundreds of thousands of beads each carrying millions of copies of a unique single-stranded DNA molecule are sequenced in parallel. If a nucleotide complementary to the template strand is flowed into a well, the polymerase extends the existing DNA strand by adding nucleotide(s). Addition of one (or more) nucleotide(s) results in a reaction that generates a light signal that is recorded by the CCD camera in the instrument. The signal strength is proportional to the number of nucleotides incorporated in a single nucleotide flow. |