A.-D. Necropsy images of mice and organs treated with MSN-HA Dylight 680 on consecutive days reveal highly specific tumor localization of siTWIST-MSN-HA complexes as compared to siTWIST-MSN (No HA) alone (C). GFP fluorescence shows all Ovcar8-IP tumor cells within the abdominal cavity (B and D). E.-F. Imaging of individual organs reveals that negligible quantities of MSN-HAs are found in the heart, liver, kidney, spleen, or lung. GFP and Diylight fluorescence is nearly all found in disseminated tumors, including lesions on the liver, kidney and spleen surfaces, with most signal emitted from the primary tumor. Units for luminescence are photons/sec/cm2/steradian.