| abstract |
The present invention involves methods of improving the Ligase Chain Reaction (LCR TM ) amplification schemes by modifying at least one probe end so that the probability of the probe contributing to spurious ligation and signal development is greatly reduced. Only after specific hybridization of the modified probe with true target are the modified ends "corrected" by endonuclease IV in a target dependent fashion to allow participation of the probe in the enzymatic ligation reaction. Specific modifications include 3' phosphate blocking groups and nucleic acid overhangs containing an abasic site at the point of ligation. Further embodiments include probes modified to contain ribonucleotide moieties which, after amplification, can be cleaved by RNase to destroy the amplification products and reduce the risk of contamination. |