Operating Cooperatively (OC) Sensor for Highly Specific Recognition of Nucleic Acids

Molecular Beacon (MB) probes have been extensively used for nucleic acid analysis because of their ability to produce fluorescent signal in solution instantly after hybridization. The indirect binding of MB probe to a target analyte offers several advantages, including: improved genotyping accuracy and the possibility to analyse folded nucleic acids. Here we report on a new design for MB-based sensor, called \u27Operating Cooperatively\u27 (OC), which takes advantage of indirect binding of MB probe to a target analyte. The sensor consists of two unmodified DNA strands, which hybridize to a universal MB probe and a nucleic acid analyte to form a fluorescent complex. OC sensors were designed to analyze two human SNPs and E.coli 16S rRNA. High specificity of the approach was demonstrated by the detection of true analyte in over 100 times excess amount of single base substituted analytes. Taking into account the flexibility in the design and the simplicity in optimization, we conclude that OC sensors may become versatile and efficient tools for instant DNA and RNA analysis in homogeneous solution

Nuclease-Containing Media For Resettable Operation Of Dna Logic Gates

We designed and tested a system that allows DNA logic gates to respond multiple times to the addition of oligonucleotide inputs. After producing an output signal, the system spontaneously resets to the background state. This system does not require any operator action to achieve reset of a DNA logic gate, and may become useful for construction of reusable DNA-based computational devices