In this paper we present a novel highly sensitive detection system for diagnostic applications. The system is designed to
meet the needs of medical diagnostics for reliable measurements of pathogens and biomarkers in the low concentration
regime. It consists of a confocal detection unit, micro-structured sampling cells, and a "Virtual lab" analysis software.
The detection unit works with laser induced fluorescence and is designed to provide accurate and highly sensitive
measurement at the single molecule level. Various sampling cells are micro-structured in glass, silicon or polymers to
enable measurements under flow and nonflow conditions. Sampling volume is below one microliter. The "Virtual lab"
software analyzes the light intensity online according to the patent pending "Accurate Stochastic Fluorescence
Spectroscopy" (ASFS) developed by FluIT Biosystems GmbH. Tools for simulation and experiment optimization are
included as well. Experimental results for various applications with relevance for in vitro diagnostics will be presented.