Ligase chain reaction
A method of detecting a specific nucleotide sequence with some similarities to polymerase chain reaction. Like PCR, it uses DNA polymerase and specific primers designed to bind to the target. However, unlike PCR, the primers are not used to amplify the DNA sequence between the primers. Instead, if the target sequence is present, both primers will hybridize so that one primer will lie directly adjacent to the second primer of the pair. In the presence of DNA ligase, these 2 primers are joined to form a single strand and the target sequence will have been effectively duplicated. In the presence of a mutation or if the target sequence is not present, the primers will not bind and ligation will not occur. As the cycle is repeated, only the target sequence (if it is present) is amplified.
Clinically, it used diagnostically, e.g. in detection of Chlamydia trachomatis in the urine.
- ↑ Landegren U, Kaiser R, Sanders J, Hood L. A ligase-mediated gene detection technique. Science. 1988 Aug 26;241(4869):1077-80. (Direct link - may require subscription)
- ↑ Wu DY, Wallace RB. The ligation amplification reaction (LAR)--amplification of specific DNA sequences using sequential rounds of template-dependent ligation. Genomics. 1989 May;4(4):560-9.
- ↑ Barany F. Genetic disease detection and DNA amplification using cloned thermostable ligase. Proc Natl Acad Sci U S A. 1991 Jan 1;88(1):189-93. (Direct link)