Data from: Deep-tissue optical imaging of near cellular-sized features

Detection of biological features at the cellular level with sufficient
sensitivity in complex tissue remains a major challenge. To appreciate
this challenge, this would require finding tens to hundreds of cells (a
0.1 mm tumor has ~125 cells), out of ~37 trillion cells in the human body.
Near-infrared optical imaging holds promise for high-resolution,
deep-tissue imaging, but is limited by autofluorescence and scattering. To
date, the maximum reported depth using second-window near-infrared
(NIR-II: 1000–1700 nm) fluorophores is 3.2 cm through tissue. Here, we
design an NIR-II imaging system, “Detection of Optically Luminescent
Probes using Hyperspectral and diffuse Imaging in Near-infrared”
(DOLPHIN), that resolves these challenges. DOLPHIN achieves the following:
(i) resolution of probes through up to 8 cm of tissue phantom; (ii)
identification of spectral and scattering signatures of tissues without a
priori knowledge of background or autofluorescence; and (iii) 3D
reconstruction of live whole animals. Notably, we demonstrate noninvasive
real-time tracking of a 0.1 mm-sized fluorophore through the
gastrointestinal tract of a living mouse, which is beyond the detection
limit of current imaging modalities.