Isoelectric Point

The isoelectric point (pI) is the pH value at which a solution becomes neutral. This means that the molecules in solution are in a state of equilibrium and have no charge.

When determining the isoelectric point, the titration method is used. In this method, a solution containing the molecule to be tested is mixed with an indicator solution. The indicator changes color depending on the acidity of the solution. When the pH reaches the isoelectric point, the indicator changes color and becomes colorless.

Determining the isoelectric point is important for understanding the properties of molecules in solution. For example, proteins have an isoelectric point, which can be used to determine their charge and interactions with other molecules. Also, the isoelectric point can be used to purify proteins from impurities and other substances that can change their properties.

In general, the determination of the isoelectric point is an important tool in biochemistry and other fields of science related to the study of molecules in solutions.