Project title: Construction of chondroitin sulfate microarray The proposal is aimed to develop a high throughput method to study the interactions between chondroitin sulfate (CS) and proteins. CS is a member of glycosaminoglycan family displaying a wide range of biological functions. Glycan Therapeutics is a company specialized in CS and other glycosaminoglycan related research products. In this phase I SBIR proposal, a CS microarray technique will be constructed. The strength of the company is capable of synthesizing structurally defined CS oligosaccharides using the enzymatic method, allowing to synthesize gram-scale of CS oligosaccharide. A single specific aim is proposed in the current application, which to build CS-microarray analysis technique covering 30 different oligosaccharides. Three experiments to support the quality control of the technology are proposed. First experiment is to couple a chemical linker to the synthesized CS oligosaccharides to allow affixation of the oligosaccharides on the array chip. Second experiment is to prepare eight fluorescently labeled CS oligosaccharides to evaluate the efficiency for the affixation to the chip. Third experiment is to identify a CS-binding protein to serve as a positive control for the CS-microarray analysis. In the phase II studies, the number of oligosaccharides array slides will be expanded to 200 to fully represent the structures of CS isolated from natural sources. The success will lead to a convenient approach for improving research in glycosciences.