Metal Cation Mediated-Capillary Electrophoresis of Nucleic Acids

摘要

Nucleic acid electrophoresis separation heavily dependsnupon gel or nongel sieving matrix. Here we propose anmetal ion mediated-capillary electrophoresis (MCE-CE)nby utilizing the nonspecific interactions of Mg2 and Ca2nand demonstrate the size, conformation, or sequencenbased separation and characterization of versatilennucleic acid molecules in free solution. Mg2 and Ca2ncan induce DNA separation at the concentrations asnlow as 100 and 50 µM, respectively. Noteworthy, thentwo naturally occurring polymorphisms of one basensubstitution that may change the secondary foldingnstructure or base stacking can be discriminated bynMCM-CE, showing its unique capability of resolvingnlength-identical but conformation-different ssDNA. Ben-nefiting from the achieved separation, we further dem-nonstrate that the folding conformation of oligomers andnits change caused by single base substitution can benpromptly sensed by online coupled fluorescence po-nlarization. We anticipate that this method will benapplicable in length polymorphism analysis, single-nstrand polymorphism analysis, hybridization analysis,nmicroRNA analysis, and study of protein nucleic acidninteractions and the conformation function relationship.