Fig. 9. Invasive activity in early- and late-passaged chondrosarcoma cells. A, a typical set of micrographs showing CS-3 cells on invasion assay membranes at 2 PDs (37 cells) and 59 PDs (283 cells). Bar, 200 µm. B, histogram showing side-by-side comparison of invasive activity (% of control) in early cultures () and late cultures (). Results are shown for the CS-2 line (2 PDs versus 106 PDs), the CS-3 line (2 PDs versus 59 PDs), the CS-4 line (2 PDs versus 58 PDs), the CS-8 line (2 PDs versus 43 PDs), and a normal chondrocyte population (2 PDs versus 18 PDs). Columns, means based on nine determinations; bars, SDs. NC, normal chondrocyte population.