Sequencing by hybridization is a class of methods for determining the order in which nucleotides occur on a strand of
DNA. Typically used for looking for small changes relative to a known
DNA sequence.
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 genes from a sample (e.g. from a tissue). It is a two-dimensional array on a solid substrate—usually a glass slide or silicon ...
with thousands to billions of synthetic
oligonucleotides
Oligonucleotides are short DNA or RNA molecules, oligomers, that have a wide range of applications in genetic testing, research, and forensics. Commonly made in the laboratory by solid-phase chemical synthesis, these small bits of nucleic acids ...
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 (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