YPD Medium and Plates with Geneticin (G418)

Agar	20 g
Yeast extract	10 g
Difco Peptone	20 g
Geneticin	300 mg
water	to 1000 ml

Add followings into 850 ml of water: Agar 20 g, yeast extract 10 g, Difco peptone 20 g, and autoclave.
In the mean time, dissolve 300 mg Geneticin into 100 ml. Sterile filter it.
After agar cools down to 50-55 C, add 50 ml of 40% percent dextrose, and 100 ml of geneticin solution. Pour your plates.

Note 1: Ammonium Sulfate in the media reduce the efficacy of G418. Therefore, when you are making "minimal media containing G418", Monosodium Glutamate (2) [1 g/L final concentration] should replace ammonium sulfate as the nitrogen source (3, 4). Geneticin (G418) will work fine in YPD medium.

Note 2: The active concentration of Geneticin is written on the bottle and varies from lot to lot (from 500 to 800 μg per mg of total dry weight). The amount used must be adjusted for each lot.

(1) Pan, X et al (2004) Molecular Cell 16, 487-496.
(2) L-Glutamic acid monosodium salt hydrate (Sigma Catalog Number: G1626)
(3) Webster and Dickson (1983). Gene, 26, 243-252.
(4) http://www.openbiosystems.com/