Recently, the term 'proteomics' was proposed to define the large-scale study of the proteins expressed by a genome. Typically, proteomic studies rely on a number of techniques, such as 2-dimensional gel electrophoresis and mass spectrometry, that have been used over the years. The current technologies have serious drawbacks in terms of financial and skilled labor requirements, automation, sensitivity and robustness. Furthermore, the current technologies often fail to identify large subsets of proteins, such as hydrophobic proteins, posttranslationally modified proteins and proteins of low abundance. It is therefore clear that proteomics is a field under development and will require novel technologies for it to become a reliable large-scale tool for the study of biological processes. Miniaturization and automation could address some of the current proteomic limitations. Recently, the development of microfabricated systems for the analysis of proteins has been reported. This paper reviews the recent development of enclosed microfluidic systems, often termed 'lab on a chip', and the development of 'array devices' for the characterization of proteins.