Publisher Summary This chapter describes the methods used for isolating and characterizing the noncellulosic polysaccharides of the primary walls of suspension-cultured sycamore cells. These procedures are applicable to the study of other types of cell walls. Cell walls form the basic structural framework of the plant, defining the shape and size of plant cells and tissues. Cell walls are classified as either primary or secondary, depending upon their mechanical properties and chemical composition. The primary cell wall is a mechanically dynamic structure encasing the cell during the period of rapid expansion that follows cell division. The secondary cell wall is, relative to the primary cell wall, a mechanically static structure that determines the shape and size of the mature cell. The chapter presents the experiments for the isolation of plant cell walls and the isolation of polysaccharides from cell walls and from extracellular polysaccharides of suspension-cultured plant cells and the chemical methods used for characterizing polysaccharides.