The platform is also highly specific: we did not observe any measurable signal in control experiments using only one Dig-conjugated DNA strand (#1 and #2, Figure ) or both strands unconjugated (#3, Figure ). We also observe no signal using anti-Dig Fab fragments (instead of intact anti-Dig antibodies), which was expected due to the monovalent nature of the Fab fragments (#4, Figure ). Furthermore, when we added saturating concentrations of non-specific antibodies, we recorded signals that were indistinguishable from background (Figure ).