Figure 4. Cluster Integrity.

Absorption spectra acquired for S1-S2₁₄ that is fully cycled from its single-stranded to its hybridized and back to its single-stranded state. First, single-stranded S1-S2₁₄ forms the violet cluster (solid line). Second, this conjugate hybridizes with its longer complement S2C₁₆ (dotted line). Third, this conjugate reacts with the isolated recognition site S2₁₆ (dashed line). The first and third spectra match, and this spectral reversibility is also accomplished in diluted solutions (Fig. S6). These results support transfer of an intact cluster between two distinct DNA binding sites.