Where is the fixed concentration of agonist and EC 50 is the concentration of agonist that results in half maximal activation of the receptor. Sometimes, IC 50 values are converted to the pIC 50 scale. IC 50 can be determined with functional assays or with competition binding assays. EC 50 represents the dose or plasma concentration required for obtaining 50% of a maximum effect in vivo. IC 50 is comparable to other measures of potency, such as EC 50 for excitatory drugs. IC 50 is commonly used as a measure of antagonist drug potency in pharmacological research. IC 50 values are typically expressed as molar concentration. The biological component could be an enzyme, cell, cell receptor or microorganism. drug) is needed to inhibit, in vitro, a given biological process or biological component by 50%.

IC 50 is a quantitative measure that indicates how much of a particular inhibitory substance (e.g. The half maximal inhibitory concentration (IC 50) is a measure of the potency of a substance in inhibiting a specific biological or biochemical function. Visual demonstration of how to derive IC50 value: Arrange data with inhibition on vertical axis and log(concentration) on horizontal axis then identify max and min inhibition then the IC50 is the concentration at which the curve passes through the 50% inhibition level.

Graphpad ic50 calculation