Movie S1.

Sca-1+cKit+ cell in intravascular location. Representative in vivo two-photon microscopy video of a bone marrow cavity with cells stained with the nuclear dye Hoechst33342 (blue), and QD570 Ab(c-Kit)NB_Tz (green), and QD612 Ab(Sca-1)NB_Tz (red). Vessels are imaged by circulating QD nanoconjugates (discontinued red line) and bone is imaged by second harmonic generation (discontinued white line). The video was slowed down to highlight the interaction of a rolling cell with the Sca-1+cKit+ cells (time is displayed in the top corner). Imaging time resolution: 1 volume per 30 seconds; imaging spatial resolution 0.6 μm/pixel, displayed a maximal z projection of 10 μm. Video shows the intravascular location of a Sca-1+cKit+ cells which interferes with flowing cells and interacts with rolling PBMNCs.