"20× Pre-C" solution

Reagent	Final concentration	Amount
Anhydrous sodium acetate	24 mg⋅mL−1	12 g
Casamino acids	100 mg⋅mL−1	50 g
L-tryptophane	100 μg⋅mL−1	50 mg
L-cysteine	1 mg⋅mL−1	500 mg
NaOH (1–10 N)	n/a	Up to pH 7.5
ddH2O	n/a	Up to 500 mL
Total	n/a	500 mL