Isoelectric Point (pI) Definition:

For an amino acid, the specific pH at which the concentration of the zwitterionic form reaches its maximum value.

Isoelectric Point (pI) Explained:

The PH level where a specific molecule carries no electrical charge. The standard level where this happens is when in PH(I). The isoelectric point is an important measurement tool when it comes to protein purification and identification. At the isoelectric point, the pH at that point typically represents the least solubility, which in effect can determine man features of a protein, i.e. mass.