Preparative isoelectrofocusing and high resolution 2-dimensional gel electrophoresis for concentration and...

We have analysed the potential of liquid phase isoelectrofocusing allied to high resolution 2-dimensional gel electrophoresis for concentrating and purifying in particular plasma proteins present in low concentrations. The primary fractionation step, liquid phase isoelectrofocusing, offers several advantages. Firstly, it allows protein profiles to be examined within defined pH ranges. Additionally, it confines the bulk plasma proteins to their respective pI ranges, allowing larger quantities of protein to be employed for the second fractionation phase. Concurrently, it concentrates proteins present at low concentrations, also by restricting them to their pI ranges. Yields are such that detailed characterisation studies of the proteins can be undertaken, providing the means of generating comprehensive data banks to complement plasma protein maps. The procedure should be applicable to a wide range of biological fluids and tissues.