Fig. 5. Fluorescence images of proliferating cells in fetal pancreas cell colonies. BrdU (100 µM) was added during the last 16 hours of 6 day culture of E15.5 pancreas cells in the presence of laminin-1 and BMP-6. BrdU incorporated into the DNAs of proliferating cells was stained with mouse monoclonal anti-BrdU (A) and isotype control IgG2a (B) antibody and visualized with fluorescein-isothiocyanate-conjugated anti-mouse immunoglobulins.