Glycine is a molecule with pI of 6.7, which is similar to the pH of stacking gel. It has advantage of low mobility, hydrophobicity and it does not associate with proteins. Glycine is a component of Tris-glycine and Tris-glycine-SDS (sodium dodecyl sulfate) running buffers for polyacrylamide gel electrophoresis. Glycine is also a component of Towbin′s transfer buffer for Western blots.