There is a need for the development of very sensitive micro-analytical techniques for measuring proteins in biological fluids and single cells. One approach to such analysis is capillary electrophoresis (CE), which is a powerful analytical tool utilizing only nanoliters of materials. However, conventional detection systems are inadequate for the analysis of very small biological samples and single cells where many analytes are present in pico- and femto-gram quantities. The use of laser-induced fluorescence (LIF) has been demonstrated to be capable of overcoming many of the shortcomings of more conventional detection systems. At DBEPS, we have designed and developed a laboratory-built LIF detector capable of measuring fluorochrome-labeled analytes at approximately 100 femtograms. Although further refinement is required to ensure uniform labeling of multiple analytes pre-analysis, research into more advanced photon detectors is underway. Presently, a complete laboratory-built CE-LIF system has been constructed and is capable of routinely measuring analytes at the 0.5 pg/ml level. An additional detector has been developed that incorporates two different laser systems, thus allowing the simultaneous detection of unknown analytes and internal standards. This detector has greatly enhanced the usefulness of the CE system. Further developments to increase sensitivity to the 1 femtogram/ml level or beyond are still progressing with the goal of developing an instrument capable of reliable measurements of single cell secretions and/or cytosol in clinical and research samples. Coupling CE with an immunoaffinity pre-analysis step has further refined the capabilities of this instrument enabling the analysis of samples in the 0.5 - 100 pg range. Development moving the electrophoresis system into a chip format has progressed due to an interactive arrangement with a commercial micro-fabrication facility in Canada. This has resulted in developments of both a chip-based immunoaffinity and a highly sensitive """"""""lab-on-a-chip"""""""". Both are now being applied to clinical analyses.
