Enzyme Activity Calculator

Enzyme Activity Calculator

The Enzyme Activity Calculator determines how much enzyme mass you need to reach a target activity in a buffer solution. Enzyme activity measures how efficiently an enzyme converts substrate to product, usually reported in units per milliliter (units/mL) or units per milligram (units/mg).

When preparing a working solution from a concentrated stock, use:

$$E_{\text{mass}} = \frac{E_{\text{desired}} \times V_{\text{final}}}{E_{\text{stock}}}$$

where $E_{\text{desired}}$ is the target activity in units/mL, $V_{\text{final}}$ is the final volume in mL, $E_{\text{stock}}$ is the stock activity in units/mg, and $E_{\text{mass}}$ is the required enzyme mass in mg.

Example: for $E_{\text{desired}} = 10$ units/mL, $E_{\text{stock}} = 5$ units/mg, and $V_{\text{final}} = 20$ mL, the required mass is $E_{\text{mass}} = (10 \times 20) / 5 = 40$ mg.

Related tools: Dilution Factor Calculator and Concentration Calculator.