Fig. 10. Schwann cell passage-dependency of laminin binding capacity and receptor expression. Laminin (10 µg/ml) was incubated in serum-free culture medium with high-passage (HPC, P27) and low-passage (LPC, P12) Schwann cells for 2 hours. Cell surface-bound laminin was visualized by immunofluorescence microscopy with laminin-specific antibody (a,b) and analyzed by flow cytometry (e, thick line shows the distribution of cell surface-bound laminin intensities for HPC, while the thin solid line is the distribution for the LPC). The level of laminin bound to the cell surface of HPC was more than 100-times higher than that bound to LPC. Flow cytometry of ß1-integrin (e) and -dystroglycan (f) reveal that ß1-integrin levels are about threefold higher in HPC, whereas -dystroglycan levels remain nearly the same in HPC and LPC. High-passaged cells continue to express the Schwann cell-specific marker S-100 (e). Bar, 10 µm (a-d).