Japanese scientists have produced a mechanism for quickly identifying DNA mutations. The most common form of genetic variation between individuals is caused by single-nucleotide differences in our DNA code. These are called single nucleotide polymorphisms (SNPs). SNPs can be used to identify disease genes and can highlight when a person is likely to develop a disease.The method uses a short strand of DNA, known as an oligodeoxynucleotide probe, attached to a glass chip. The probe contains DNA bases complementary to those in the DNA strand containing the SNP of interest, except that one base is replaced by a vinyl-containing nucleoside known as cvP. When the target DNA was placed onto the chip and shone ultraviolet light on it, the cvP reacted with an adenine base on the target DNA, in a reaction known as photocrosslinking. This can then be detected by the scientists using florescent light which indicates if any mutations are present by either making the chip flouresce or not as only photocrosslinking occurs if all nuclotides match.
http://www.rsc.org/Publishing/ChemTech/Volume/2007/09/DNA_chips.asp
