Fibronectin distribution on the surfaces of young and old human fibroblasts

Indirect immunofluorescence was used to examine the distribution of fibronectin fibrils on young and old cultures of human fibroblasts. In young cultures, the pattern of fibronectin fibril pattern was generally parallel to the long axis of spread cells. In contrast, the pattern on old cells displayed extensive, interconnecting networks of randomly oriented fibrils. The differences observed in the two cultures were independent of both cell density and substrate composition.