The intensity of staining and nuclear localization of nBmp2 differ between M-phase and the other phases of the cell cycle. 10T1/2 cells were cultured on slides for 24 hrs in the absence of serum, and then serum was replaced at time zero. Cells were immunostained using an anti-Bmp2 antibody (green) to visualize nBmp2 in cells at different stages of the cell cycle. Nuclei were stained with TO-PRO-3 (red), and cells were examined by laser confocal microscopy. Panels a-e show mitotic cells imaged at the 4 hr. time point. (a) A cell in late prophase (arrow) shows more nBmp2 staining than surrounding non-mitotic cells, with the least intense staining in the region of chromosome condensation. A metaphase cell is also visible in this frame. Cells in metaphase (b), anaphase (c), and telophase (d) (arrows) show more intense Bmp2 staining than surrounding non-mitotic cells, and staining is reduced where condensed chromosomes are located. (f) Non-mitotic cells imaged at the 8 hr. time point show nuclear localization of nBmp2.