Figure 1.

(A) Conjugation of hyaluronic acid (HA) with Cy5.5 (excitation 675 nm, emission 694 nm). (B) Conjugation of antibody with IRDye800 (excitation 770 nm, emission 786 nm). (C) Schematic of dual-tracer fluorescence optical imaging. The IRDye800 conjugated antibodies were injected via tail vein 24 h before local administration of Cy5.5-HA. Fluorescence imaging was performed 60 min later with a near-infrared filter set (excitation 704 nm, emission 745 nm longpass). The signals from Cy5.5-HA and IRDye800-mAb were then unmixed based on their unique spectra to reflect tumor metastasis within the sentinel lymph node.