Dr. Weigel has made substantial research contributions in several fields, including the discoveries of multiple coated pit pathways for receptor-mediated endocytosis and of the enzyme responsible for hyaluronan biosynthesis. He has had a long-standing interest in the biochemistry and the biology of hyaluronan. His group was the first to identify and isolate the gene for hyaluronan synthase. Dr. Weigel's laboratory also developed the use of structurally defined iodinated hyaluronan oligosaccharides of high specific radioactivity to detect and to study specific hyaluronan receptors and binding proteins. This approach has recently enabled his laboratory to purify the liver endothelial cell receptor that removes circulating hyaluronan fragments from the blood by receptor-mediated endocytosis.