Working with Antibiotics
|Solvent||Stock Concentration to
|Ampicillin||Amp||100mg/ml||H2O||1000x||Plates only last 2 weeks|
|Chloramphenicol||Cam||20mg/ml||100% Ethanol||1000x||Use a final volume of 5 ug/ml for S. pneumoniae (stock is a 4000x solution for this purpose)|
|Cycloheximide||Chx||100mg/ml||DMSO||1000x||Toxic to fungi and animals (including humans)
Use protective gear; work in chemical hood.
|Erythromycin||Ery||250mg/ml||100% Ethanol||1000x||There are 2 different concentrations in the -20 freezer. Use final concentration of 0.25ug/ml for S. pneumoniae. Precipitates in the freezer; before use, put in dry heating block at 37° for 2 hours before use. Vortex occasionally during this incubation. It will come out of solution as soon as it is added to media; stir media gently and continue to use.|
|Kanamycin||Kan||50mg/ml||H2O||1000x||Plates only last 2 weeks; Use a final concentration of 250 ug/ml for S. pneumoniae (stock is a 200x solution for this purpose)|
|Tetracycline||Tet||10mg/ml||70% Ethanol||1000x||Light sensitive
Wrap tubes and plates in aluminum foil; Use a final concentration of 1 ug/ml for S. pneumoniae.
Prepare 10mL of antibiotics at a time (less, for antibiotics that degrade quickly, like Ampicillin, Kanamycin, and Tetracycline).
If the solvent is not water, we can assume that the antibiotics will be sterilized by the solvent. After creating the appropriate concentration, they should be aliquoted into sterile microcentrifuge tubes by 500µl and put in the -20 freezer.
If the solvent is in water, prepare the solution in a 50ml conical tube. Filter sterilize the solution through a 0.22µm filter and a 10mL syringe, all in the biological hood using sterile technique. Aliquote into microcentrifuge tubes by 500µl and put in the -20 freezer
Be sure to label the aliquots with the antibiotic, concentration, and date. Please wrap Tetracycline aliquots in foil.