Preparation of Neo (G418) Stock:

1. Prepare a solution of 75 mg/ml (of active fraction) of Neo in sterile PBS or RPMI unsupplemented.

a. Some G418 bottles contain 5g with 65% activity. This is actually 3.25g of active G418. Prepare a solution of 3.25g of active G418 with 45ml of either sterile PBS or RPMI.

2. Mix the G418 and PBS or RPMI until all of the solid is dissolved.

3. Sterile filter the solution in a tissue culture hood.