High selectivity detection of point mutation by DNA photochemical cross-linking

We describe the investigation of the photochemical ligation based DNA chip for enhanced discrimination of single nucleotide polymorphisms (SNPs). Results show that the reaction takes place over a period of hours on the target, reaching more than 50% stage in 10 min. Significantly, a single mismatch in the target sequence yielded extremely little ligated product, with a measured rate that was 10(3)-fold lower than the complementary case.