Patent ID: 8993239
Filing Date: 2015-03-31
Classification: C12Q

Abstract:
1. A nucleic acid capable of forming a hybrid with a target nucleic acid sequence and capable of forming a stem-loop structure if no hybrid is formed with the target sequence, said nucleic acid comprising (a) a nucleic acid portion comprising (b) an effector and an inhibitor, wherein the inhibitor inhibits the effector when the nucleic acid forms a stem-loop structure, and wherein the effector is active when the nucleic acid is not forming a stem-loop structure, and wherein the effector is a luminescent label, in particular a fluorescent label, and the inhibitor is a quencher, characterised in that the nucleic acid is constructed in a method comprising (i) designing the sequence of (a1) such that the ΔG of the hybrid of the sequence of (a1) with its target sequence is in the range of about −17 to about −25 kcal/mol under hybridisation conditions which comprise hybridisation in a buffer having a Mg (ii) designing the sequences of (a2) such that the ΔG of the hybrid of the sequences of (a2) is smaller than 0 in the absence of the target sequence and higher than the ΔG of the hybrid of the sequence of (a1) with its target sequence.