Sequencing by hybridization
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 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 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. However hybridization of oligonucleotides is still used in some sequencing schemes, including hybridization-assisted pore-based sequencing, and reversible hybridization.
