The pH at which a protein has no net charge. At a pH above the isoelectric point, a protein acts as a base. At a pH below the isoelectric point, it acts as an acid. A solution of proteins or amino acids has its minimum conductivity and viscosity at pI.
Isoelectric point is the pH of a solution or dispersion at which the net charge on the macromolecules or colloidal particles is zero. In electro-phoresis there is no motion of the particles in an electric field at the isoelectric point.
pH value of a hydrophilic sol (electrolyte) at which it will not migrate in an electrical field.
The pH of a solution in which a protein has no net charge. At the proteinâ€(tm)s isoelectric point, it will not migrate in the presence of an electric field.
The isoelectric point (pI) is the p H at which a molecule carries no net electrical charge. In order to have a sharp isoelectric point, a molecule must be amphoteric, meaning it must have both acidic and basic functional groups. Proteins and amino acids are common molecules that meet this requirement.
