USING SINGLE MOLECULAR PROBES TO DETECT DNA AND DNA-BINDING PROTEINS

摘要

We describe single-molecule assays for ultrasensitive detection of DNA oligomers and DNA-binding proteins. We exploit a new paradigm of molecular detection, where ligand binding is detected through the conformational change induced in the probe molecule. Single DNA molecules bearing the recognition site for target molecules are used as probes for ultra-sensitive detection of DNA or DNA-binding proteins. Since the amount of DNA available from cell extracts is very small, standard practice in order tomake detection practical is to perform PGR amplification of the DNA. This time-consuming process can sometimes also introduce mistakes in the sequence of the amplified product. Also most detection methods need the target DNA molecules to be labeled. Ourmethod requires neither PGR amplification nor labeling. Fewer steps make the method simpler, easier and cheaper.