Membrane chromatography has significant potential for use in biopharmaceutical purification processes. However, currently available membrane chromatography devices give poor resolution and therefore their use is restricted to polishing applications, typically carried out in the flow-through mode. Laterally fed membrane chromatography (or LFMC) was developed specifically for carrying high-resolution multi component protein separations. Recent studies have shown that resolution obtained with LFMC is comparable to that obtained with equivalent resin-based packed bed chromatography. Therefore, LFMC combines high-resolution with high-productivity, a highly desirable attribute in any purification technique. In this paper we explain the workings of LFMC based on theoretical and experimental analysis of hydraulic flow-path and residence time distribution. Factors likely to affect efficiency of LFMC are discussed using a simple electrical circuit analogy. (C) 2016 Elsevier B.V. All rights reserved.