Darvill's research focuses on structurally characterizing the five major noncellulosic carbohydrates of plant primary cell walls homogalacturonan, rhamnogalacturonan I and II, xyloglucan, and glucuronoarabinoxylan. Plant primary cell walls control the rate and direction of cell growth that determine ultimately the shapes of cells, tissues, and organs; they form a barrier to pathogens, are the source of oligosaccharins that elicit plant defense responses to pathogens, and participate in controlling plant growth and development. New analytical techniques are continually developed to isolate and determine the complicated structures and functions of these molecules. Interactions between wall-matrix polysaccharides is being characterized by examining the cell-, tissue-, and species-dependent expression of cell wall epitopes using well-characterized monoclonal antibodies.