June 15, 2010 (Vol. 30, No. 12)
Richard A. A. Stein M.D., Ph.D.
According to Jonathan M. Rothberg, Ph.D., CEO, founder, and chairman of Ion Torrent, his company’s semiconductor sequencing technology represents a quantum advancement in DNA sequencing. Ion Torrent™ is the first commercial sequencing method that does not use light, it is also the first PostLight™ sequencing method since Sanger and Gilbert won the Nobel Prize for DNA sequencing in 1980, he reports.
Ion Torrent directly translates chemical information into digital information by combining the simplest sequencing chemistry with a novel semiconductor chip—one that images chemistry instead of light. When a nucleotide is incorporated into a DNA strand by means of Watson-Crick complementary base pairing, a hydrogen ion is released. The charge from that ion is detected by Ion Torrent’s ion sensor—millions of simultaneous sequencing reads at a time. Information about the base pair sequence is then directly converted into digital information.
“Nothing is more direct than measuring the hydrogen ion released during synthesis, or more efficient than leveraging the trillion dollars that have gone into the semiconductor technology,” says Dr. Rothberg.
“Ion Torrent technology uses no lasers, no enzymes, and no fluorescence,” he explains. As a result, Ion Torrent is free from many of the errors that enzymatic sequencing approaches create as well as of the data overload that image analysis in light-based sequencing approaches require.
Ion Torrent semiconductor sequencing technology is feasible because of the exponential improvements made in semiconductor technology over the past 40 years, also known as Moore’s law. “We don’t have to wait for 40 years to benefit from Moore’s Law, we just have to leverage the last 40 years of advances in semiconductor technology with our proprietary designs,” says Dr. Rothberg.