Single nucleotide polymorphisms(SNPs) are the most frequent type of DNA sequence variation of individuals. They are defined by the presence of two alternative bases at a particular position in a DNA sequence and occur about one per 500-1000bp in the h...
Single nucleotide polymorphisms(SNPs) are the most frequent type of DNA sequence variation of individuals. They are defined by the presence of two alternative bases at a particular position in a DNA sequence and occur about one per 500-1000bp in the human genome. The recent completion of the first reference sequence of the human genome has provided a basis for comprehensive analysis of sequence variation in man. The identification and dense mapping of SNPs is of considerable significance for association studies of complex diseases, pharmacogenetics, population genetics and physical mapping. Their use as genetic markers is favored by their high abundance, low mutation rate and the easy automation of typing. With the development of ABI Prism 3100 or 3700 system, single nucleotide primer extension, we car get a straightforward and large-scale method for validation of or comparative genotyping of known SNPs and point mutations. In the mini sequencing primer extension reaction, a DNA polymerase is used specifically to extend a primer that anneals immediately adjacent to the nucleotide position to be analyzed with a single labeled nucleoside triphosphate complementary to the nucleotide at the variant site. The reactor allows highly specific detection of point mutations and single nucleotide polymorphisms(SNPs) without direct sequencing. Because all SNPs can be analyzed with high specificity at the same reaction conditions, mini sequencing is a promising reaction principle for multiplex high-throughput genotyping assays. It is also a useful tool for accurate quantitative PCR-based analysis. This review discusses the advanced biotechnique.