This Small Business Innovation Research (SBIR) Phase II project proposes to develop a novel, low cost laboratory instrument for genetic analysis and single molecule studies. The technology is suitable for the detection and identification of DNA and RNA through fluorescent hybridization probes without the need for Polymerase Chain Reaction (PCR) amplification, or for proteins and small molecules through fluorescence immunoassays. The general scheme is based on single molecule detection (SMD) and utilizes the two-color cross-correlation spectroscopy (TC-FCCS) technique with coincident detection analysis scheme to simultaneously probe ten focal regions of a microfluidic assay. High efficiency single photon detectivity Geiger mode microavalanche photodiode (uAPD) arrays will function as detection elements.<br/><br/>The commercial application of this project will be on biological and medical research, and on the drug development process. Examples of potential applications range from the study of conformational dynamics and interactions of macromolecules to biochemical kinetics of single molecules.