from R&D Magazine by Tim Studt
Modern DNA sequencing began in the mid-1970s following 20 years of development after James Watson and Francis Crick’s 1953 initial determination of the structure of DNA. This sequencing development was made by Frederick Sanger in the Medical Research Centre at the Univ. of Cambridge, U.K., in 1977, for which he (and Walter Gilbert at Harvard Univ. for a different sequencing process) won the Nobel Prize in Chemistry in 1980. Sanger’s capillary electrophoresis-based method (termed Sanger Sequencing), which selectively incorporates chain-terminating dideooxynucleotides by DNA polymerase during in vitro DNA replication, had been widely and exclusively used for nearly 25 years. The Sanger method was automated by Applied Biosystems in the mid-1980s, which then became the main workhorse technology for the sequencing efforts by the Francis Collins-led team at the National Institutes of Health (NIH) and the J.Craig Venter-Celera team in the highly competitive race to be the first to sequence the human genome in the Human Genome Project (HGP).
The success and publicity surrounding the HGP in the 1990s helped increase demand for low-cost and high-throughput DNA sequencing. Several new next-generation sequencing (NGS) methods were developed in the late-1990s and implemented into commercial DNA sequencers by 2000. These developments focused on technologies that parallelize the sequencing process, thereby concurrently producing thousands to millions of sequences. In ultra-high-throughput sequencing systems, 500,000 or more sequencing runs by synthesis operations can be performed in parallel.
A small number of companies currently produce NGS systems including Illumina, Life Technologies (now part of Thermo Fisher Scientific), 454 Life Sciences (Roche Diagnostics) and Pacific Biosciences. The biggest technological issues with NGS systems include the time, cost and complexity of sample preparation, and the data quality, reliability and uptime of the expensive sequencing systems. “There is still room to improve the flexibility of NGS sample preparation chemistries to accept lower-quality and lower input DNA/RNA,” says Marcy Engelstein, Senior Marketing Manager at Beckman Coulter Genomics, Danvers, Mass. (Read more…)
Source – R&D Magazine