Abstract: The present invention describes sample loading devices for use in polyacrylamide gel electrophoresis systems. The sample loading devices comprise alternating areas of absorbent membranes and diffusion barriers, where the diffusion barriers are formed by the application of some form of energy, such as heat, pressure, laser energy, RF energy or the like. The present invention also describes devices and methods for making sample loading devices, and methods of loading samples into polyacrylamide gel electrophoresis systems.