I previously tried gelatin zymography using precast 0.1% gelatin gels (Novex) and it worked fine (gave me some 'clearance zones'). I came accross immersing zymography in some papers and wanted to try it, as it seems cheaper and easier. I have used precast SDS-PAGE gel with no substrate (Mini-Protean) and applied the same protocol as previously. The only change was that 0.1% gelatin was added to my developing buffer. After staining with SimplyBlu SafeStain (also used previously) it seems like only a half of gel took up the stain and unfortunately not the half where I was expecting to see proteolytic activity. Any ideas what went wrong?

Regards,

Jadwiga