Dexamethasone Treatment of Mice

We use water-soluble Dex from Sigma (D2915). It says on the bottle how many mg/g is actually Dex. The calculations below are for a bottle where the powder was 65mg/g. Dex

For i.p. injection 5 mg/kg

• Makes 15mL stock solution of 1mg/mL
• dissolve 0.231g Dex powder in 15mL PBS

BW (g) X 0.005 = injection volume (mL)

Calculation

65mg dex/        =       15mg dex/        =  0.231g
1000mg powder          ? mg powder   

For drinking water administration ~1mg/kg/day

• Makes 1L of drinking water
• dissolve 0.092g in 1L water

Calculation

• 1mg Dex/kg/day because mice drink ~5mL /day so want 0.2 mg Dex/kg/mL
• average mouse weighs 0.03kg so want 0.006mg Dex/mL or 6mg/L

 
65mg dex/                         =    6mg dex/                =>    X=  0.092g 
1000mg solid powder            ? (X) mg powder   

• This assumes that the mice are about 30g and they drink 5mL/day.