Abstract: A micro-electric detector provides conductivity or impedance based measurements of a test sample placed in a microchannel of a micro-analysis system. The detector includes a pair of electrodes disposed on opposing sidewalls of the microchannel to create a detection zone in the microchannel between and adjacent to the electrodes. A variety of test samples can be monitored by the detector, such as particulate-containing fluids and biological materials including living cells and subcellular structures. The detector can be integrated on-chip using micromachining techniques with a variety of micro-analysis systems.