Ion Torrent is a semiconductor sequencing technology that uses micro holes in a chip to directly link chemical and digital information by detecting the release of hydrogen ions during DNA synthesis. It is simpler, faster, and more flexible than other sequencing methods and allows for applications like small genome sequencing and PCR sequencing. The technology operates by detecting pH changes in micro pores associated with DNA synthesis, converting chemical signals into digital information.

1. Ion Torrent Semiconductor Sequencing
Technology

2. • Ion Torrent is the latest generation sequencing technology. Its
core technology is the use of semiconductor technology in
chemical and digital information to establish a direct link. DNA
chain is fixed In the semiconductor chip micro holes, and followed
by the incorporation of ACGT. With the incorporation of each
base, hydrogen ions are released, which can be detected at the
bottom of each hole through the detection of H+. Compared with
other sequencing technologies, this sequencing system is
simpler, faster and more flexible.

3. Technical principle:

4. • In the semiconductor chip micro hole, DNA polymerase lets single
stranded DNA as template, according to the principle of base
complementarity, and synthetise complementary DNA chain.
When a base is stretched by a DNA chain, a proton is released,
resulting in a local pH change.

5. • The surface of each micro hole in the Ion Torrent semiconductor
sequencing chip contains about 1 million DNA molecules. When
sequencing, a continuous flow of nucleotides go through the chip
micro pores. If the nucleotide is complementary to the DNA
molecule in the specific pore, the nucleotide is synthesized into
the DNA molecule, and the hydrogen ion is released, and also the
PH of the pore solution is changed. After the ion sensor detects
the change of PH, chemical information is changed to the digital
electronic information.

6. • If the DNA chain contains two identical bases, the voltage signal
is double. If the base does not match, then there is no hydrogen
ion release, and there is no change in the voltage signal. This
method belongs to the direct detection of DNA synthesis.
Because of less CCD scanning, fluorescence excitation and other
steps, the synthesis of the inserted base can be detected in a few
seconds, which greatly shortens the running time.

7. • There are Ion SphereTM particles in Micro pores. The particles
contain the DNA template, which can release a proton combined
with a nucleoside, and finally resulting in pH changes in the micro
hole. Sensing layer detects the change of pH, and converts the
chemical signal into digital signal.

8. Main application:

9. • Small genome sequencing (e.g. de novo genome sequencing of
microorganisms and viruses, mitochondrial DNA sequencing,
etc.)
• PCR sequencing (e.g. 16S metagenomics sequencing)
• Targeted re sequencing
• Genome / full exome validation

10. • The original article:
• http://www.storeboard.com/blogs/health/ion%C2%A0torrent-
semiconductor-sequencing-technology/585394