Practice question

Tetramethylethylenediamine accelerates polyacrylamide gel formation by catalyzing decomposition of ammonium persulfate into reactive sulfate free radicals and stabilizing their activity through electron donation. Without TEMED, radical generation proceeds slowly, leading to incomplete or excessively delayed polymerization and poor pore reproducibility. Acrylamide plus bisacrylamide crosslinking forms porous matrix essential for molecular sieving during electrophoresis. Visualization functions belong to Coomassie, silver or fluorescent dyes, while DNA stains like ethidium bromide intercalate nucleic acids, and bromophenol blue serves only as anionic tracking front. TEMED itself has no dye or staining properties.