Authors: J.G. Williams, B.L. Reynolds, K. Keefe and J.P. Anderson
Affilation: LI-COR Biosciences, United States
Pages: 239 - 242
Keywords: structural DNA, polymerase, SYBR, fluorescent nanoparticles, nucleotides
Structural DNA nanoparticles functionalized with phosphate-linked nucleotide triphosphates (dNTPs) were tested as a source of dNTPs for DNA polymerase. The particles were prepared by strand-displacement polymerization from a self-complementary circular template. An intercalating dye (SYBR-101) was joined to the gamma-phosphate of a dNTP by a PEG linker, and the dye-dNTP conjugate was covalently bonded to the nanoparticles. Imaged by AFM, these functionalized particles appear as condensed fuzzy balls with diameters between 50-150 nm. They emit a bright fluorescent signal, detected in 5 msec exposures with a signal-to-noise of 50 when imaged using a TIR fluorescence microscope. A DNA polymerase, adapted by directed evolution to the efficient utilization of phosphate-modified dNTPs, inefficiently utilizes dNTPs supplied from the nanoparticles.