Abstract
Scattering of shorter-wavelength visible light limits the
fluorescence imaging depth of thick specimens such as whole
organs. In this study, we report the use of four newly synthesized
near-infrared and far-red fluorescence probes
(excitation/emission, in nm: 644/670; 683/707; 786/814; 824/834)
to image tumor cells in the subpleural vasculature of the intact
rat lungs. Transpelural imaging of tumor cells labeled with
long-wavelength probes and expressing green fluorescent protein
(GFP; excitation/emission 488/507 nm) was done in the intact rat
lung after perfusate administration or intravenous injection. Our
results show that the average optimum imaging depth for the
long-wavelength probes is higher (