Ampicillin stock solution (x 1000)

How to prepare Protocol for ampicillin 100 mg/ml stock solution stock (x 1000).

• Weigh ~1 g ampicillin sodium sulfate powder (Fisher 1760-25) in a Falcon 50 mL tube.
• Add water to the 10 mL mark and vortex. Adjust the volume with water if necessary.
• Filter through 0.22 µm membrane with a large syringe.
• Store at -20 in 1 ml aliquots.

Final concentration for E. coli should be 100 µg/ml. This is close to the upper limit recommended by ATCC (see below).

Kanamycin (1000X stock at 50 mg/ml)

Dissolve 1 gram of Kanamycin sulfate in 20 ml distilled water. Vortex to make sure completely dissolved. Sterile by filtering through a 0.2 µm filter. Aliquot and store at -20°C.

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.

Antibiotics

Final concentrations generally recommended:

• 100 µg/mL Ampicillin

• 12.5 µg/mL Tetracycline

• 50 µg/ml Kanamycin

• 200 µg/mL G418

• 300 µg/mL HygromycinB

• 200 μg/ml clonNAT

[ atcc.png](atcc_recommendations_antibiotic_concentrations.pdf)