Ligase chain reaction

Both target and signal amplification systems have been successfully employed to detect and quantitate specific nucleic acid sequences in clinical specimens. Polymerase chain reaction (PCR), nucleic acid sequence-based amplification (NASBA), transcription-mediated amplification (TMA), strand displacement amplification (SDA), and ligase chain reaction (LCR) are all examples of enzyme-mediated, target amplification strategies that are capable of producing billions of... 

An amplification system that has been successfully commercialized is called the ligase chain reaction (B4). The basis for this reaction lies in using two small single-stranded DNA probes of 10 to 20 bases in length to anneal to target DNA and an enzyme called DNA ligase to link the two probes. Twenty to 50 cycles of this reaction can yield sufficient amplified product. 

Mycobacteria of the Mycobacterium avium complex are implicated in disseminated bacterial infections in AIDS patients. RFLP studies followed by hybridization with radiolabeled probe specific for an insertion sequence in M. avium (IS 1311) have been useful for typing M. avium stains (R2). A variety of molecular techniques are available for the diagnosis of Chlamydia trachomatis infection. In addition to PCR, a method based on the ligase chain reaction has also been found to be sensitive to the detection of C. trachomatis infection in urine specimens collected from male and female subjects (VI). The differentiation between low-risk genotypes of human papilloma virus (HPV 6 or 11) from genotypes of high... 

HCV and HIV-1). The bDNA assay is being much employed for the quantification of messenger RNA. Moreover, for the detection of viral and pathogenic disorders based on alkahne-phosphatase-sensitive dioxetanes, several assay methods are available these include the Polymerase-Chain-Reaction (PCR) amphfication, probe ligation, strand-displacement amplification and the ligase chain reaction. ... 

Cheng et al. [211] described an NCE-LIF system for the rapid separation and quantitative detection of ligase chain reaction (LCR) products amplified from the lac I gene on a silicon-glass chip. LCR is a useful molecular technique for... 

Ligase chain reaction (LCR) Recently developed amplification method used to... 

There are other techniques that can be used to amplify DNA. For instance, the ligase chain reaction (LCR) was achieved on a Si-glass chip for detecting known... 

The most recent addition to the amplification techniques is the ligase chain reaction, LCR, which differs from all the other amplification techniques, which are based on the use of DNA or RNA polymerizing enzymes. In contrast, LCR uses the ability of DNA ligase to join two synthetic DNA oligonucleotides... 

Wiedmann M, Wilson WJ, Czajka J, Luo J, Barany F, Batt CA. Ligase chain reaction (LCR)—overview and applications. PCR Methods Appl 1994 3 S51-64. 

Buimer M, van Doornum GJ, Ching S, Peerbooms PG, Plier PK, Ram D, et al. Detection of Chlamydia trachomatis and Neisseria gonorrhoeae by ligase chain reaction-based assays with clinical specimens from various sites implications for diagnostic testing and screening, J Clin Microbiol 1996 34 2395-400. 

Chernesky MA, Jang D, Lee H> Burczak JD> Hu H, Sellers J, et al. Diagnosis of Chlamydia trachomatis infections in men and women by testing first-void urine by ligase chain reaction. J Clin Microbiol 1994 32 2682-5. 

Hook EW III, Smith K, Mullen C, Stephens J, Rine-hardt L, Pate MS, et al. Diagnosis of genitourinary Chlamydia trachomatis infections by using the ligase chain reaction on patient-obtained vaginal swabs. 

Lee HH, Chernesky MA, Schachter J, Burczak JD, Andrews WW, Muldoon S, et al. Diagnosis of Chlamydia trachomatis genitourinary infection in women by ligase chain reaction assay of urine. Lancet 1995 345 213-6. 

Mahony J, Chong S, Jang D, Luinstra K, Faught M, Dalby D, et al. Urine specimens from pregnant and nonpregnant women inhibitory to amplification of Chlamydia trachomatis nucleic acid by PCR, ligase chain reaction, and transcription-mediated ampUfica-... 

Puolakkainen M, Hiltunen-Back E, Reunala T, Suhonen S, Lahteenmaki P, Lehtinen M, et al. Comparison of performances of two commercially available tests, a PCR assay and a ligase chain reaction test, in detection of urogenital Chlamydia trachomatis infection. J Clin Microbiol 1998 36 1489-93. 

A third type of contamination is unique to PCR and other amplification methods, such as the ligase chain reaction. It involves the inadvertent contamination of a new reaction with the aerosolized products of a previous reaction. As shown in Table 2, as little as 10"7 pi of a tube of amplified DNA can contain 103 molecules of target (C4). Recommended precautions (K13) involve the use of positive-displacement pipets and the physical separation of areas where PCR reactions are analyzed from those where new reactions are setup. In laboratories that use these precautions, contamination is infrequent, and, when it does occur, is usually at the 1- to 100-molecule level. However, in addition to these procedural measures, it would be useful to have chemical or enzymatic methods of selectively inactivating amplified DNA—similar to the sterilization procedures used to inactivate large numbers of cultured viruses or bacteria. 

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