Anonymous asked in Science & MathematicsChemistry · 6 months ago

Medication Prep?

Hi guys,

I’m having a really tough time with concentration. I just never understood how to do it but I have a 10 mg/ml stock solution. I need to dilute it so I can give 8 mg/kg to mice. How do I calculate this?!

1 Answer

  • 6 months ago

    If an average mouse weighs 20 grams, then a mouse will get 8 mg /kg X 0.020 kg = 0.16 mg of the drug. You don't indicate what kind of volume you want to inject into the mice, but let's say you want to use 0.1 mL injections. So, the concentration of the drug that you inject would be 0.16 mg/0.1 mL or 1.6 mg/mL

    If you wanted to inject 50 mice, you would need 5 mL of the diluted drug. 

    C1V1 = C2V2

    10 mg/mL (V2) = 1.6 mg/mL (5 mL)

    V1 = 0.8 mL

    So, if you take 0.8 mL of your stock solution and dilute it to 5 mL, the resulting solution will be 1.6 mg/mL

    So to calculate the specific volume to be given to an individual mouse:

    8 mg/kg X mass of mouse in kg / 1.6 mg/mL = ___ mL of injection

    Hope that helps....

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