SYNOPSIS Dr Chai is a Senior Research Fellow of the Glycosciences Laboratory and Wellcome Trust supported Carbohydrate Microarray Resource, Department of Medicine. As a trained chemist he became interested in the structural aspects of carbohydrate molecules of biomedical importance. After a period of work at the Institute of Chemistry, Chinese Academy of Sciences (Beijing) and the Department of Pharmaceutical Chemistry & NIH National Bio-Organic Biomedical Mass Spectrometry Resource Center, University of California at San Francisco, he joined the Glycosciences Laboratory at the MRC Clinical Research Centre in 1988, which later became part of the Imperial College London. RESEARCH INTERESTS His research programme has been aimed at characterizing the sequences and understanding the roles of oligosaccharide chains of glycoproteins, glycolipids and polysaccharides in recognition systems of biological and medical importance, including: i) the design and application of integrated strategies to tackle the difficult area of structure and function assignments of oligosaccharides, and ii) the development of methods for structural analysis of bioactive oligosaccharides, using mass spectrometry as the principal technique, and their application in different biological settings. MAIN CONTRIBUTIONS As a chemist working at the interface of chemistry and biology, his main contribution to the glycochemistry/glycobiology field has been the design, development and application of integrated strategies to tackle the challenging area of structures and functions of carbohydrate molecules to understand their biological/biomedical roles. A highlight has been the establishment, together with colleagues, of the first oligosaccharide microarray system in the world, which has found many important applications in the fields of infection and immunity. He has also developed various mass spectrometric strategies, particularly negative-ion electrospray tandem mass spectrometry, for sequence determination of bioactive oligosaccharides, and as a result, many oligosaccharides with novel sequences have been isolated from different natural sources. Highlights include the detection of natural killer cell marker HNK-1 epitope on O-glycans with a novel O-mannosyl core in brain and demonstration of the high prevalence (30%) of the ‘yeast-type’ 2- and 2,6-linked O-mannosylated sequences among the O-glycans; and identification of sulphated Lewis a/x oligosaccharides as novel ligands for E-selectin. As the lead scientist in the analytical/structural aspects, in collaboration with James Beeson of the WEHI, Melbourne, he has defined the essential structural motif on chondroitin sulphate A and hyaluronic acid for adhesion of P. falciparum-infected erythrocytes and the key structural requirements on heparan sulphate-like molecules which can block P. falciparum merozoite invasion of erythrocytes. This study contributed to a better understanding of host-cell molecules involved in the pathogenesis of placental infection by the parasite and suggesting possible development of novel therapeutic approaches to malaria. Link to the full list os publications: http://www.imperial.ac.uk/people/w.chai/publications.html Link to the Mass Spectrometry Facility: http://www.imperial.ac.uk/glycosciences/research/mass-spectrometry/