An evaluation of gradient acrylamide gel electrophoresis and acrylamide gel isoelectric focusing for the primary separation of complex mixtures of proteins: Comparison of one- and two-dimensional analytical procedures

Abstract

Pore gradient electrophoresis and two-dimensional acrylamide gel electrophoresis were compared with gel isoelectric focusing and gel isoelectric focusing combined with pore gradient electrophoresis for the separation of complex mixtures of proteins ( viz. serum, cerebrospinal fuid, urine, and bacterial cell extract). Based on simplicity, sensitivity, and reproducibility, the acrylamide gel procedures were found superior to the gel isoelectric focusing techniques. Of all the techniques examined, the most sensitive (total number of proteins detected) and that which produced the most informative protein patterns, was a two-dimensional polyacrylamide gel electrophoretic technique. With this procedure, the proteins are first separated in a homogeneous gel, then in a continuous, concave 2–30% gel gradient, at right angles to the first separation. Thus, pore gradient electrophoresis offers to all fields of biology a highly sensitive and versatile tool for the analyses of proteins and peptides.