Immobilized pH Gradient (IPG) Strips are specialized gel strips used in isoelectric focusing that contain a fixed, stable pH gradient chemically bound within the gel matrix. Unlike traditional carrier ampholyte based gradients, IPG strips provide highly reproducible and stable pH profiles, allowing precise separation of proteins based on their isoelectric points. These strips are widely used in two-dimensional gel electrophoresis (2D-PAGE) and proteomics for improved resolution, sensitivity, and consistency in protein analysis.