Ampicillin stock solution

How to prepare Protocol for ampicillin 200 mg/ml stock solution stock (x 1000).

• Weigh 2 g ampicillin sodium sulfate powder (Fisher 1760-25) in a Falcon 15 mL tube.
• Add water to the 10 mL mark and vortex. Add more water if necessary.
• Filter through 0.22 uM membrane with a large syringe.
• store at -20 in 1 ml aliquots.

final concentration for E. coli should be 200 µg/ml. This is 2-10 times the recommended by ATCC (see below), but the higher concentration avoid satellite colonies.

Geneticin(G418) stock solution 200 mg/mL (x 1000).

Geneticin (Gibco's brand name) or G418 (generic name) is used to select for yeast that have the KanMX resistance marker. We make G418 stock solution at 200 mg/ml (1000x) and use a final concentration of 200 μg/ml in solid or liquid media. The working solution is stored in 1 mL aliquots marked with a capital "G" at -20°C. Put these tube is the box marked "Antibiotics" in the -20 freezer. Goldstein, A.L., McCusker, J.H., 1999. Three new dominant drug resistance cassettes for gene disruption in Saccharomyces cerevisiae. Yeast 15, 1541–1553.

Tetracycline 12.5 mg/ml

Add 125 mg Tetracycline Hydrochloride (MW = 480.898 g/mol) powder to a 15 mL FALCON tube. Add 7 mL of Ethanol 99.5 or 96%. Add water to 10 mL. Aliquot 1 mL per tube and store at -20C. For XL1-Blue use 12.5 µg/mL Tetracycline.

[ atcc.png](atcc_recommendations_antibiotic_concentrations.pdf)