Immobilized pH gradient
Immobilized pH gradient (IPG) gels are the acrylamide gel matrix co-polymerized with the pH gradient, which result in completely stable gradients except the most alkaline (>12) pH values. The immobilized pH gradient is obtained by the continuous change in the ratio of Immobilines. An Immobiline is a weak acid or base defined by its pK value.[1] This alternative method eliminates the problems of gradient instability and poor sample loading capacity associated with carrier ampholyte pH gradient.[2] Commercial precast IPG gels are available.