Fig. 5. Analysis of MMP9 in tumor xenografts. (A) Equal protein amounts of crude tumor extract were analyzed in gelatin zymography. Solid and open arrowheads indicate migration of proMMP9 and MMP9 forms, respectively, according to the activity detected in HT-1080 medium (H). (B) Tumor sections were incubated with DQ-gelatin (a,d,g,j; green in merged images) to detect in situ gelatinolytic activity; nuclei were stained with DAPI (b,e,h,k; blue in merged images). Magnification, x400.