Bis-Acrylamide, or N, N′-Methylenebis(acrylamide), is a cross linking agent that polymerizes with Acrylamide to introduce crosslinking polyacrylamide chains, resulting in polyacrylamide gel formation. This gel produced is commonly used for electrophoretic separation of nucleic acids and proteins. The ratio of bisacrylamide to acrylamide used influences the porous characteristics of the polyacrylamide gel.