Antibiotics

Writing/Editing Credit: Mark Mandel, Tiffany Lowe-Power

Preparation of 1000x stocks

NOTE: Our first Tet stocks are not 1000x. I prepped 10 mg/ml stocks. But we need 30 ug/ml final concentration. So add 1.5 ml tet per 500 ml CPG

Prepare 20 mls at a time and aliquot

Antibiotic	Color	Abbr	Concentration (mg/ml)	Solvent	Stock notes
Kanamycin	PURPLE	Kan	25	dH20	Filter
Gentamicin	BROWN	Gm	10	dH20	Filter
Spectinomycin	BLACK	Sp	40	dH20	Filter
Tetracycline	GREEN	Tet	30	dH20	Filter; Keep dark (foil wrap)
Ampicillin	RED	Amp	100	dH20	Filter
Chloramphenicol	Yellow	Cam	25	dH20	Filter

Note that the dry gentimicin is stored at room temperature, but most dry antibiotics are stored at 4C.

For each stock aliquot approximately 1.2 ml per 1.5 ml tube and store in antibiotics box at -20 °C. Label with colored stripe on lid and concentration (e.g. 50 for 50 mg/ml).

Note that there is additional information about making antibiotic-containing media listed under media.

Filter refers to filter sterilizing with 0.22 um filters.

Working concentrations for E. coli and Ralstonia

These stocks are at 1000x concentration, so add 1/1000th volume for regular use (e.g. 500 ul to 500 ml medium). If selecting in a minimal medium, a lower antibiotic concentration may be necessary.