Single nucleotide polymorphisms
Several technologically sophisticated high-throughput techniques have been recently developed for the study of human single nucleotide polymorphisms and the diagnosis of point mutations in human diseases. However, there is also a need for simple and inexpensive techniques suitable for clinical services and small research laboratories. Minisequencing meets the latter requirements. It is simple, non-radioactive and can be easily multiplexed by adding oligonucleotide tails of increasing size to the sequencing oligonucleotide primers.
We describe the application of two different fluorescence-based techniques (ddNTP primer extension and single-strand conformation polymorphism (SSCP)) to the detection of single nucleotide polymorphisms (SNPs) by capillary electrophoresis. The ddNTP primer extension technique is based on the extension, in the presence of fluorescence-labeled dideoxy nucleotides (ddNTP, terminators), of an unlabeled oligonucleotide primer that binds to the complementary template immediately adjacent to the mutant nucleotide position.