Immunofluorescence of Caveolin-1 in primary notochordal cells in monolayer culture. Immunofluorescence images of the notochordal cell clusters on days 0, 2, 4, 6, 8, and 10 in culture. Scale bar: 50 μm. Nuclear staining (Topro-3) and Caveolin-1 staining are depicted in blue and green, respectively. Caveolin-1 protein was located in intracellular membranes, as suggested by the inhomogeneous appearance of the immunolabeled membrane-embedded marker, and in the notochordal cell membrane.