TEMED (N,N,N’,N’-Tetramethylethylenediamine) is a catalyst used in the polymerization of acrylamide and bisacrylamide to form polyacrylamide gels. It accelerates the reaction between acrylamide and the initiator (typically ammonium persulfate), enabling rapid gel formation. TEMED is essential in preparing gels for protein and nucleic acid separation in electrophoresis.