6-Amino-2-(2-deoxy-β-D-ribofuranosyl)-2,5-dihydro-4H-pyrazolo-[3,4-d]-pyrimidin-4-one is a derivative of 4-Amino-6-methyl-8-(2-deoxy-β-D-ribofuranosyl)-7(8H)-pteridone (A615680), which is a highly fluorescent adenosine analogue, which in a dimethoxytrityl, phosphoramidite protected form, can be site-specifically inserted into oligonucleotides through a 3',5'-phosphodiester linkage using an automated DNA synthesizer. Molecular Formula: C10H13N5O4 Molecular Weight: 267.24