Abstract: The present invention provides methods for detecting a target nucleic acid in a sample by, for example, incubating the target nucleic acid with a detection probe containing a nucleic acid sequence complementary to at least a portion of the target nucleic acid and a nuclease enzyme that specifically cleaves double-stranded nucleic acids. Hybridization between the detection probe and the target nucleic acid thereby leads to cleavage of the detection probe, releasing a portion of the probe attached to a detectable agent. The portions of the digested probes attached to the detectable agent can be separated from unbound probe and detected in order to determine the presence of the target nucleic acid in the sample. Thus, the invention enables rapid and accurate analysis of a sample for the presence of desired nucleic acid biomarkers.

Abstract: The present invention provides methods of detecting a target nucleic acid in a sample using a duplex-specific nuclease (DSN), such as Kamchatka crab nuclease or RNaseH, and compositions for DSN reactions. For example, a composition of the invention may include a sample having a target nucleic acid, a nucleic acid probe, a DSN, and a buffer, and the composition may be maintained at about 90° C. to about 97° C. The target nucleic acid may be detected, for example, by hybridizing the target nucleic acid to a detection probe and digesting the resultant duplex using the duplex-specific nuclease, thus releasing a detectable component of the probe, which can be separated from unbound probe for detection or detected in situ. The invention also features methods of catalyzing hybridization or stabilizing hybridization between nucleic acid strands using DSNs.