CHEMISTRY CALCULATORS
Isoelectric Point Calculator
Calculate the isoelectric point of amino acids and proteins for precise biochemical analysis.
What is the Isoelectric Point Calculator & How does it work?
The isoelectric point (pI) of a molecule is the pH at which it carries no net electrical charge. For amino acids, this occurs when the number of positive charges from protonated amino groups equals the number of negative charges from deprotonated carboxyl groups.
For proteins, the pI is determined by the average pI of its constituent amino acids. The calculation involves summing the contributions of each amino acid’s charge at different pH levels and finding the point where these charges balance out.
For proteins, the pI is determined by the average pI of its constituent amino acids. The calculation involves summing the contributions of each amino acid’s charge at different pH levels and finding the point where these charges balance out.
pI = \frac{\sum (n_i \times pK_{a,i})}{\sum n_i}
ni = number of amino acids of type i, pKa,i = pKa value for amino acid i
Parameters
Result—
Results are for informational purposes only and do not constitute professional advice.