Fig. 3.

In vivo dose and time window optimization of DARPin-800CW conjugates. A Tumor MFIs and TBRs as a function of time after intravenous administration of 3, 6, or 9 nmol Ac2-800CW or Ec4.1-800CW in subcutaneous HT-29_luc2 tumor-bearing mice. B TBRs as a function of time after intravenous administration of 6 nmol Ac2-800CW, Ec4.1-800CW, and negative control tracer Off7-800CW in subcutaneous HT-29_luc2 tumor-bearing mice. C NIRF-color merge and NIRF images of subcutaneous HT-29_luc2 tumor-bearing mice at 24 h post-injection of Ac2-800CW, Ec4.1-800CW, or Off7-800CW. Images were captured using the clinical Artemis NIRF imager at a similar exposure time of 150 ms, allowing real-time imaging. White arrows indicate an example of a representative tumor. NIRF, near-infrared fluorescence; p.i., post-injection; TBR, tumor-to-background ratio. **P < 0.01