Nanosphere of Northbrook, Ill., has received US Patent No. 8,323,888, "Nanoparticles having oligonucleotides attached thereto and uses therefor." The claimed methods include contacting a nucleic acid with particles that have oligonucleotides attached to them. In one embodiment, the oligos are attached to nanoparticles and have sequences complementary to portions of the sequence of the nucleic acid. A detectable change, preferably a color change, is brought about as a result of the hybridization of the oligos on the nanoparticles.