I was running 2 gels one is 12% Bis-Tris and the other is 16% tricene gel, the BT gel showed the main protein band and 3 faint bands underneth it,the 16 % Tricene gel showed the main band plus a messy band underneth it that is strongly stained and not faint at all much thicker, also the faint bands in BT and the thick band in tricene are both in the same molecular weight