| abstract |
The invention relates to a method of detecting a target nucleic acid sequence in a sample by contacting the sample with a detectable probe to hybridize the probe to the target sequence, and detecting the hybridized probe. The method comprises the steps of: a) providing a detectable probe comprising two free nucleic acid end parts which are capable of hybridizing to two at least substantially neighbouring regions of the target sequence, b) hybridizing the probe ends to the target sequence under hybridizing conditions, c) convalently connecting the ends of the hybridized probe with each other to form a cyclized structure interlocking with the target molecule, d) subjecting the target sequence to non-hybridizing conditions and/or exonuclease activity to remove any non-cyclized probe from the target sequence, thereby retaining only the cyclized probe bound to the target molecule, e) optionally repeating steps b) to d) one or more times, and f) detecting the presence, and if desired, location of remaining labelled probe as indictative of the presence of the target nucleic acid sequence. The invention also relates to a detecting reagent or probe as well as a kit for use in the method. |