Gelling solution (per sample)

Reagent	Final concentration	Amount (first gelling solution)	Amount (second gelling solution)
Monomer solution∗	n/a	188 μL	141 μL
4-Hydroxy-TEMPO (4-HT)	0.1 g/l	4 μL	3 μL
Tetramethylethylenediamine (TEMED)	2 g/l	4 μL	3 μL
Ammonium persulfate (APS)	2 g/l	4 μL	3 μL
Total		200 μL	150 μL

Prepare on ice and use immediately. Add TEMED or APS last to prevent early gel polymerization.