Single nucleotide polymorphisms (SNPs) are the most common type of sequence variation in the human genome. These single-base variations at key sites in DNA are believed to be associated with susceptibility to certain diseases and differential response to pharmaceutical therapies. The detection and analysis of SNPs have typically relied on Sanger sequencing and electrophoresis for genomewide studies or hybridization-based methods whose accuracy may be inadequate.
Pyrosequencing reads SNPs by chemiluminescence Now Pyrosequencing AB of Uppsala, Sweden, offers a new sequencing technology for the genotyping of SNPs with greater than 99 percent accuracy. In the Pyrosequencing™ system, immobilized single-stranded DNA template-sequencing primer hybrids are incubated with enzymes and substrates provided in the SNP reagent kit. The unit then adds each of four dNTPs to the reaction one at a time; DNA polymerase will only catalyze incorporation of the nucleotide complementary to the next base in the template, releasing pyrophosphate (PPi). ATP ...
