Molecular Beacons: Hybridization Probes for Detection of Nucleic Acids in Homogeneous Solutions

摘要: Molecular beacons are oligonucleotide probes that can report the presence of specific nucleic acids in homogeneous solutions (Tyagi and Kramer, 1996). They usefulin situationswhere it is either not possible or desirable to isolate probe-target hybrids from an excess hybridization probes, such as real-time monitoring polymerase chain reactions sealed tubes detection RNAs within living cells. hairpin-shaped molecules with internally quenched fluorophore whose fluorescence restored when they bind a target acid (Figure 1).They designed way loop portion molecule probe sequence complementary molecule. The stem formed by annealing arm sequences on ends sequence. A fluorescent moiety attached end one quenching other arm. keeps these two moieties close proximity each other, causing be energy transfer. Since quencher non-fluorescent chromophore emits receives heat, unable fluoresce. When encounters molecule, forms hybrid longer more stable than its rigidity length preclude simultaneous existence hybrid. Thus, molecular beacon undergoes spontaneous conformational reorganization forces apart, causes move away leading restoration which detected.