The dilution equation M₁V₁ = M₂V₂ relates the concentration and volume before and after dilution.

• M₁ = Initial concentration
• V₁ = Initial volume (volume of stock to use)
• M₂ = Final concentration (always lower)
• V₂ = Final volume (total volume after dilution)

Serial dilution is used to create a range of concentrations by repeatedly diluting by the same factor.