Endy:Preparing Antibiotic Stocks

Ampicillin

Stocks & Usage

• Stock Concentration - 50mg/ml in H₂O
• Aliquots - 100μl and 500μl
• Working Concentration - 50μg/ml

Preparation of 80ml stock solution

• Ampicillin is kept in the 4C fridge in 68-564D. It is light sensitive.
• Weigh 4g of ampicillin into a small weigh boat.
• Add 80ml of milliQ to a 250ml bottle.
• Add the ampicillin to the milliQ
• Mix/vortex so all the ampicillin goes into solution.
• Filter sterilize the solution into a falcon tube using a 20ml syringe and a 200nm filter.
• Aliquot into pcr tubes and 1.7ml eppendorfs.
• Store at -20C.
• Store the small aliquots in the small box and the big aliquots in the larger box.

Kanamycin

Stocks & Usage

• Stock Concentration - 10mg/ml in H₂O
• Aliquots - 200μl and 1ml
• Working Concentration - 20μg/ml

Preparation of 80ml stock solution

• Kanamycin is kept in the 4C fridge in 68-564D. It is light sensitive.
• Weigh 800mg of kanamycin into a small weigh boat.
• Add 80ml of milliQ to a 250ml bottle.
• Add the kanamycin to the milliQ
• Mix/vortex so all the kanamycin goes into solution.
• Filter sterilize the solution into a falcon tube using a 20ml syringe and a 200nm filter.
• Aliquot into pcr tubes and 1.7ml eppendorfs.
• Store at -20C.
• Store the small aliquots in the small box and the big aliquots in the larger box.

Tetracycline

Stocks & Usage

• Stock Concentration - 5mg/ml in 70% Ethanol
• Aliquots - 200μl and 1ml
• Working Concentration - 20μg/ml

Preparation of 80ml stock solution

• Tetracycline is kept in the 4C fridge in 68-564D. It is light sensitive.
• Weigh 400mg of tetracyline HCL into a small weigh boat.
• Dilute 95% Ethanol to 70% using milliQ water.
  • Adding 20ml of milliQ to 60ml of 95% ethanol gives 80ml of 71% ethanol.
• Add 80ml of 70% Ethanol to a 250ml bottle.
• Add the tetracycline HCL to the ethanol.
• Mix/vortex vigorously so all the tetracycline goes into solution.
• Filter sterilize the solution into a falcon tube using a 20ml syringe and a 200nm filter.
• Aliquot into pcr tubes and 1.7ml eppendorfs.
• Store at -20C and protect any unused stock solution from light.
• Store the small aliquots in the small box and the big aliquots in the larger box.

Chloramphenicol

• Stock concentration - 34mg/ml in 100% Ethanol
• Aliquots - 1ml
• Working concentration = 25μ/ml (Stringent), 170μ/ml (relaxed)

Preparation of 80ml stock solution

• Chloramphenicol is kept at room temperature. It is near our other chemicals
• Weight 2.72g of chloramphenicol sulfate into a small weight boat.
• Add 80ml 100% EtOH to the chloramphenicol
  • 95% EtOH probably works just fine, but I haven't tried it.
• Mix/vortex vigorously so all the chloramphenicol goes into solution.
• Aliquot into 1.7ml eppendorfs.
  • N.B. There is no need to filter sterilize, as it is in EtOH.
• Store at -20C.

Streptomycin

Stocks & Usage

• Stock Concentration: 50mg/ml in H₂O
• Aliquots - 0.5 ml
• Working Concentration - 10-50μg/ml

Preparation of 40ml stock solution

• Streptomycin is kept in the 4C fridge in 68-564D. I don't think it is light sensitive (not stored in opaque bottle).
• Weigh 2g of streptomycin into a small weigh boat.
• Add 40ml of milliQ to a 100 or 250ml bottle.
• Add the streptomycin to the milliQ
• Mix/vortex so all the streptomycin goes into solution.
• Filter sterilize the solution into a falcon tube using a 60ml syringe and a 200nm filter.
• Aliquot into 1.7ml eppendorfs.
• Store at -20C.