In vivo detection of cancer cells with immunoconjugated fluorescent probes by macro zoom microscopy and two-photon microscopy

We developed a near infrared fluorophore-conjugated anti-Carcinoembryonic antigen (CEA) antibody for mice bearing tumor of CEA expressing cells, and demonstrated in vivo optical imaging by macro zoom microscopy. In the result, tumors of CEA-expressing cancer cells were specifically detected in vivo. Furthermore, cancer-specific fluorescence images were acquired at subcellular level in vivo by two-photon microscopy. In preclinical applications, the lymph node micrometastasis was also successfully visualized by two-photon microscopy. These results suggest that two-photon excitation microscopy in combination with an immunoconjugated probe could be widely adapted to cancer detection in clinical settings.