 fluorescent 
 nucleotide analogues , such as 2-aminopurine ( 2ap ) and 
 pyrrolo - c ( pyc ) , have been extensively used to study nucleic acid 
 local conformational dynamics in bulk experiments . here 
 we present 
 a proof - of - principle approach using 2ap and pyc fluorescence at the 
 single - molecule level . 
 our data show that ssdna , dsdna , or rna containing 
 both 2ap and pyc can be monitored using single - molecule fluorescence 
 and a click chemistry immobilization method . 
 we demonstrate that this 
 approach can be used to monitor dna and rna in real time . 
 this is 
 the first reported assay using fluorescent nucleotide analogs at the 
 single - molecule level . 
 we anticipate that single 2ap or pyc fluorescence 
 will have numerous applications in studies of dna and rna , including 
 protein - induced base - flipping dynamics in protein  nucleic acid 
 complexes . 
Supplementary Material