Table 1.
Lifetime characteristics of commercial NIR fluorophores. Emission wavelengths are taken from product literature. Mean lifetime ± the standard deviation are derived from monoexponential fit of images taken at time points from 1 min to 24 h following fluorophore injection with the mouse supine or prone, depending on the organs of interest. Only pixels with peak intensity >10% of the maximum intensity were considered in the fit (to avoid low-intensity noisy pixels). The standard deviation for all pixels was ∼2 to 3× the values listed here. τ±(ps) for Kodak X-Sight 761 shows lifetime shortening in the liver over 14 h and for Atto 740 lifetimes in the kidneys and bladder, respectively. Alexa 750 is antibody conjugated.
| Fluorophore | λem (nm) | τ±(ps) |
|---|---|---|
| Indocyanine green | 835 | 700±18 |
| Osteosense 750 | 780 | 835±47 |
| Kodak X-Sight 761 | 789 | 1343±30−1158±12* |
| IRDye 800 | 794 | 906±23 |
| Genhance 750 | 775 | 1007±23 |
| Atto 740 | 764 | 1130±54, 1003±63† |
| Alexa 750‡ | 779 | 616±26 |