Sequencing by hybridization is a class of methods for determining the order in which nucleotides occur on a strand of
DNA
Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of al ...
. Typically used for looking for small changes relative to a known
DNA sequence
A nucleic acid sequence is a succession of bases within the nucleotides forming alleles within a DNA (using GACT) or RNA (GACU) molecule. This succession is denoted by a series of a set of five different letters that indicate the order of the nu ...
.
The binding of one strand of DNA to its complementary strand in the DNA double-helix (known as
hybridization) is sensitive to even single-base mismatches when the hybrid region is short or if specialized mismatch detection proteins are present. This is exploited in a variety of ways, most notably via DNA chips or
microarrays
A microarray is a multiplex lab-on-a-chip. Its purpose is to simultaneously detect the expression of thousands of biological interactions. It is a two-dimensional array on a solid substrate—usually a glass slide or silicon thin-film cell� ...
with thousands to billions of synthetic
oligonucleotides found in a genome of interest plus many known variations or even all possible single-base variations.
The type of sequencing by hybridization described above has largely been displaced by other methods, including sequencing by synthesis, and
sequencing by ligation (as well as pore-based methods). However hybridization of oligonucleotides is still used in some sequencing schemes, including hybridization-assisted pore-based sequencing, and reversible hybridization.
Examples of commercial systems
*
Affymetrix
Affymetrix is now Applied Biosystems, a brand of DNA microarray products sold by Thermo Fisher Scientific that originated with an American biotechnology research and development and manufacturing company of the same name. The Santa Clara, Calif ...
(true sequencing-by-hybridization)
* NABsys (Hybridization-assisted pore-based sequencing)
* Complete Genomics Inc. (reversible-hybridization of probes that call-out a single base with each hybridization)
See also
*
Sequencing by ligation
References
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DNA sequencing
Laboratory techniques