The sensitivity and specificity of the optical modality can be enhanced by the use of highly absorbing compounds as contrast agents. Novel macrocyclic cyanine and indocyanine bioconjugates that absorb and emit light in the near infrared region of electromagnetic spectrum are disclosed. These compounds are especially useful for endoscopic, localized photoacoustic, and sonofluorescence imaging, detection and therapy of tumors and other abnormalities.
