2 replies to this topic

[SF_HK]

HI,

I'm not sure about my calculations.

I need to treat my cells with 500ug/ml of G418. HOwever, I'm not sure how to make this.  The bottle says 736ug/mg?

[klinmed]

SF_HK, on Apr 9 2009, 10:22 AM, said:

HI,

I'm not sure about my calculations.

I need to treat my cells with 500ug/ml of G418. HOwever, I'm not sure how to make this.  The bottle says 736ug/mg?

When G418 is produced it is not 100% active. The manufacturers determine the active fraction by bioassay. Your powder contains 736/1000 x 100 = 73.6% active G418.

If you want to make a 50 mg/ml stock solution of ACTIVE  G418 you therefore need to weigh out 1000/736 x 50= 67.93 mg of G418 for each ml of stock solution. I usually make this  x100 stock in a buffer (100 mM HEPES pH 7.3), but many people use PBS. It should be filter-sterilized and stored frozen in aliquots.

It is wise to determine the concentration of drug that works optimally in your system. This is easily done by performing a kill curve.

Hope this helps.

[chromatin]

SF_HK, on Apr 9 2009, 03:22 AM, said:

HI,

I'm not sure about my calculations.

I need to treat my cells with 500ug/ml of G418. HOwever, I'm not sure how to make this.  The bottle says 736ug/mg?

Here is recipe for you:
http://www.bioprotocols.info/model_organis...edia-plates.php