       Document 0898
 DOCN  M9620898
 TI    Detection of HCV RNA by the asymmetric gap ligase chain reaction.
 DT    9602
 AU    Marshall RL; Laffler TG; Cerney MB; Sustachek JC; Kratochvil JD; Morgan
       RL; Abbott Laboratories, Molecular Diagnostics, Abott Park, Illinois;
       60064, USA.
 SO    PCR Methods Appl. 1994 Oct;4(2):80-4. Unique Identifier : AIDSLINE
       GENBANK/M58335
 AB    The ligase chain reaction (LCR) and the gap ligase chain reaction (gLCR)
       are exponential amplification techniques for the detection of DNA
       sequences in a sample. Both techniques depend on the enzyme, DNA ligase,
       to join adjacent probes annealed to a DNA molecule. However, DNA ligase
       joins DNA inefficiency on an RNA target. Consequently, LCR and gLCR
       cannot amplify RNA efficiency. RNA detection methods using LCR or gLCR
       require a cDNA synthesis step. The carryover of four dNTPs from the cDNA
       reaction inhibits gLCR. Although LCR can use cDNA reaction products
       directly, background generated by blunt-end ligation does not allow the
       high sensitivity typically needed for HIV or HCV detection. The
       asymmetric gap ligase chain reaction (AGLCR) is a modification of gLCR
       that allows for the detection of RNA by using < or = 3 of the 4
       nucleotides in the cDNA step and the gLCR step. Fewer than 50 copies of
       synthetic RNA transcript can be reproducibly detected. HCV, an RNA virus
       with no DNA intermediate, was chosen as the initial RNA model system.
       HCV antibody-positive and normal samples were analyzed, and the results
       were found to correlate with the results obtained using nested RNA-PCR.
       AGLCR provides a new nucleic acid amplification technique that can aid
       in the diagnosis of disease when the detection of RNA is critical.
 DE    Base Sequence  DNA Probes  DNA, Complementary  Hepatitis C/DIAGNOSIS
       Hepatitis C Viruses/GENETICS/*ISOLATION & PURIF  Human  Molecular
       Sequence Data  Polydeoxyribonucleotide Synthetases/*METABOLISM
       Polymerase Chain Reaction/*METHODS  Predictive Value of Tests
       RNA-Directed DNA Polymerase/METABOLISM  RNA, Viral/*ANALYSIS  JOURNAL
       ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).

