Fig. 2.

Hybridization of DNA/nanoparticle conjugates with complementary DNA. (a) Nanoparticle conjugates containing one or two of the thiolated oligonucleotides indicated were purified from a gel as in Fig. 1a, mixed with an equal volume (5 μl) of complementary DNA (cDNA, 100 μM) or not as indicated, and subjected to electrophoresis as in Fig. 1. The gel was gold-stained. (b) Nanoparticle conjugate containing two 20-residue oligonucleotides was purified from a gel as in Fig. 1a, mixed with an equal volume (5 μl) of complementary DNA (from left to right, 0, 4 μM, 8 μM, 16 μM, 31 μM, 62 μM, 125 mM, 250 mM, and 500 mM), and subjected to electrophoresis as in Fig. 1. The gel was not stained.