McClean: Geneticin/G418 Stock Solution
Geneticin (Gibco's brand name) or G418 (generic name) is used to select for yeast that have the KanMX resistance marker. We keep G418 stock solutions at 200mg/ml (1000x) and use a final concentration of 200μg/ml in solid and liquid media. The working solution is stored in the 4°C fridge, additional aliquots are stored at -80°C.
- Geneticin (Cat # 11811-023 from Gibco)
- 1X PBS, pH 7.4
- Syringe and 0.45μM Syringe filter (PALL Life Sciences Cat #2010-09)
Generally it is easiest to dissolve the entire container of G418 at once (especially if it is a small 1g container).
- Calculate the amount of PBS to add to the vial to get a 200mg/ml 'active' concentration.
- For example: 710μg/mg means that 710μg out of 1000μg are active, or that the Geneticin is 71% active. Therefore, to make a stock solution of 200mg/ml active Geneticin you need to add 1000/710*200=281.6901mg/ml of Geneticin. The vial contains 1g of Geneticin, so you need to dissolve the contents of the vial in 1000mg/281.6901mg=3.55ml total volume.
- Sterile filter the drug using a syringe and a 0.45μm filter.
- Store stock at -80°C and working stock solution at 4°C
Please write in here when you make a new stock solution and how you made it, how many tubes, etc. Also add a note to the "Yeast Media Antibiotic Concentrations" sheet on the front of the 4°C fridge.
*Megan N McClean Made stock on 11/30/2011. Geneticin Lot #919813, activity 701ug/mg. 1000/701*200= 285.3067; 1000/ 285.3067=3.505ml. Dissolve contents of the entire 1g vial in 3.505ml total volume of 1x PBS. Sterile-filted, aliquoted in 500ul in eppendorfs. Left one tube at 4°C and put the others at -80°C
- Taylor D. Scott 16:08, 22 March 2016 (EDT): Made stock on 03/22/2016. Geneticin (G418) from Santa Cruz Biotechnology (sc-29065A) Lot #E1512. Activity 745 ug/mg. Activity 745 ug/mg. 100/745*200=268.456; 1000/268.456=3.72ml. Dissolve 1g in 3.72 ml 1x PBS. Sterile-filtered, aliqouted in 500ul in 1.5ml eppendorfs. Put at -80°C.
Please feel free to post comments, questions, or improvements to this protocol. Happy to have your input!
Please sign your name to your note by adding '''*~~~~''': to the beginning of your tip.
- Megan N McClean 14:01, 23 September 2011 (EDT)
or instead, discuss this protocol.