Patent ID: 7238477

Claim:
A method comprising: a) obtaining nucleotides covalently linked to gold or silver, or gold or silver nanoparticle(s), wherein the nucleotide and nanoparticles are linked via a terminal reactive cross-linking group, selected from the group consisting of epoxide groups, azido groups, triazine groups, arylazido groups and diazo groups; b) synthesizing one or more nucleic acid molecules comprising the gold or silver, or gold or silver nanoparticles; c) immobilizing the nucleic acid molecule of step (b) on a solid substrate; d) sequentially releasing nucleotides from one end of one or more nucleic acid molecules via an exonuclease; e) identifying the released unlabeled nucleotides in a buffer comprising an alkali-metal halide salt by Raman spectroscopy; and f) determining the sequence of the nucleic acid molecule.