Figure 5

Zymographic assay of gelatinase activity. Medium supernatants of 20 ml culture medium (medium control) as well as 20 ml conditioned medium from 10⁷ U937 cells, pMTH1-U937 cells and asCD11b-U937 cells in the absence or presence of 5nM TPA for 72 h, respectively, were 18-fold concentrated and subjected to SDS-PAGE containing 2 mg/ml of gelatine. Following incubation with MMP enzyme buffer, the gels were stained with 0.4% Coomassie blue and afterwards destained again to visualize the appearance of gelatinase activity by light bands against the dark background. The molecular weight markers on both sides of the gels indicate the size of the MMPs exhibiting gelatinase activities.