Fig. 4. Western blot analysis of S100 proteins expressed in endothelial cells (ECV). 35 µg of total protein extract was loaded in each lane of a pre-cast 4-20% Tris-glycine gradient SDS PAGE gel and blotted onto the nitrocellulose membrane. Various rabbit anti-S100 antibodies were used as primary antibodies, and signals were detected by horseradish-peroxidase-conjugated goat anti-rabbit antibody and enhanced chemiluminescence. The following S100 proteins were identified in ECV — S100A13 (lane 1), S100A6 (lane 2), S100A1 (lane 3), S100A4 (lane 5), S100A5 (lane 6) and S100B (lane 7). S100A3 was not detected in this cell line as shown in lane 4. # indicates monomeric protein, and the dimeric and polymeric forms are seen above these.