Immobilized pH gradients in capillary tubes and two‐dimensional gel electrophoresis

Isoelectric focusing in mixed carrier ampholyte‐immobilized pH gradients (CA‐IPG) is an effective way to separate proteins by charge. A method to prepare CA‐IPG in capillary tubes and the description of the equipment used are outlined. Two‐dimensional gel electrophoresis patterns of human serum and liver biopsies, with isoelectric focusing and CA‐IPG as the first dimension, are presented. The comparison with two‐dimensional gel electrophoresis patterns obtained by conventional carrier ampholyte pH gradient separation shows the excellent resolution and potential of this technique.