<i>In vivo</i> imaging analysis with the E1-reporter monobody in tumor xenograft mice.

<p>(A) Measurement of luminescence in mice injected with different concentrations of E1-Rluc8. PC3 and HeLa cells were transplanted into 6-week-old Balb/c nude mice via subcutaneous injection (n = 3). After tumor formation, the indicated amounts of E1-Rluc8 and coelenterazine were intravenously injected via the tail vein, and luminescence images were acquired at the indicated times with the NightOWL <i>in vivo</i> imaging system (left). The luminescence intensities measured in tumor areas at 6 h were graphed (right). (B) Luminescence maintenance in mice injected with E1-Rluc8 for 24 h. E1-Rluc8 (60 μg) and coelenterazine were intravenously injected via the tail vein into PC3 tumor mice (n = 5), and luminescence images were obtained at the indicated times (left). The luminescence intensities in tumor tissues were measured with the NightOWL <i>in vivo</i> imaging system and graphed (right). (C) Detection of the remaining E1-Rluc8 in PC3 tumor tissues. Tumor tissues were collected at the indicated times from mice injected with E1-Rluc8 and stained with FITC-conjugated anti-6×His antibodies (green). hEphA2 was stained with mouse anti-hEphA2 antibody and Alexa 555-conjugated anti-mouse IgG (red). Cell nuclei were stained with DAPI (blue). Scale bar, 10 μm.