Molecular Beacons and Other Hairpin Probes

Stem-loop (hairpin) DNA oligomer probes provide increased specificity of target recognition as compared with linear DNA probes. Invention of molecular beacons, a variant of stem-loop oligonucleotides, which are able to fluoresce upon hybridization but are ‘‘dark’’ in the absence of the target, made possible real-time monitoring of hybridization process. A variety of robust assays using diverse, structurally constrained oligonucleotides have been developed that exploit endless number of formats and detection methods. Hairpin DNA oligonucleotides are also used as different components in many DNA amplification methods providing higher specificity and lower background. Thus, these structured probes are an indispensable tool in modern biotechnology and diagnostics.