The
isoelectric point (
pI,
pH(I),
IEP), is the
pH at which a particular
molecule carries no net
electrical charge. The standard nomenclature to represent the isoelectric point is pH(I), although pI is also commonly seen, and is used in this article for brevity. The net charge on the molecule is affected by pH of its surrounding environment and can become more positively or negatively charged due to the gain or loss, respectively, of protons (H
+).