Fig. 1. Laminins assemble into two distinct extracellular matrices on Schwann cell surfaces. Laminin-1 and laminin-2/4 were each incubated with Schwann cells. Surface-bound laminin was visualized following fixation and immunostaining with anti-laminin primary and FITC-conjugated secondary antibodies. (a,b) Laminin-1 incubated with Schwann cells for 4 hours at 10 µg/ml accumulated on cell surface showing dense reticular distribution. Insert shows higher magnification view of the boxed area. Phase image of the same field is shown. (c,d) Level of endogenous laminin was negligible. (e) Laminin-1 at lower concentration (2 µg/ml) showed less coverage with two distinct patterns clearly resolved: reticular (boxes) and fibrillar (arrows). (f) Laminin-2/4 assembled similar structures but had different concentration dependency. Shown is laminin-2/4 at 20 µg/ml. (e',f') High magnification view of boxed areas on e and f shown as examples of reticular pattern. Boxed areas are shown magnified in insets e' and f' to define the reticular pattern. (g) Example of a fibular structure is shown. Bars, 10 µm.