Chip-based clinical assays: towards analysis of physiological samples

There are a number of challenges, both engineering and chemical, which still need to be overcome before the use of so-called miniaturized total chemical analysis systems, or /spl mu/TAS, becomes well established in the clinical domain. These are related to the complex nature of physiological media, which are inherently incompatible with microchannels having cross-sectional dimensions on the order of micrometers. The high surface-to-volume ratios of microfluidic devices are the primary concern, since biomolecules are prone to increased adsorption in these systems. Special consideration must therefore be given to analysis of protein-containing matrices in microflow systems, and analysis conditions adjusted to the type of analyte and chip substrate in question.