Fig. 1. SDF1 is a chemoattractant for C2C12 cells. (A) C2C12 cells were grown in 90% DMEM and 10% FCS to subconfluency and subsequently tested for SDF1-dependent (10 ng/ml) and HGF-dependent (HGF, 10 ng/ml) chemotaxis in a modified Boyden chamber assay as described in Materials and Methods. Data represent the mean ± s.d. from three independent experiments. Note that the migratory response elicited by SDF1 was similar to that induced by HGF. *P<0.001; Co, control. (B) Checkerboard analysis demonstrating a directed migratory (chemotactic) response of C2C12 cells towards SDF1. Numbers of migrated cells were determined in a Boyden chamber in which either only the lower well received SDF1 (10 ng/ml) or in which the concentration gradient was eliminated by adding identical concentrations of SDF1 to both the lower and the upper well (10 ng/ml each). Note that C2C12 cells fail to migrate through the filter when no SDF1 concentration gradient is present. *P<0.001; Co, control.