Isoelectric point is the point at which the overall charge of the protein is zero or we can also say that the protein has a neutral charge.

The isoelectric point is significant in protein purification because it represents the pH where solubility is typically minimal.

**Formula to calculate isoelectric point.**

The pKa value is one method used to indicate the strength of an acid.

**Example:**

Calculate the isoelectric point of glycine, whose pK1= 2.34 and pK2= 9.6 .

Therefore, the isoelectric point of glycine is 5.97.