The vitreous of most mammals contains low concentrations of three polymeric macromolecules, collagen, hyaluronan and beaded fibrils. To determine whether the beaded fibrils may have a localized function, or whether all three of these polymers could contribute to the structure and/or strength of the vitreous gel, the distribution of collagen and beaded fibrils in the central and cortical regions of the bovine vitreous was studied. The polymers were separated by isopycnic centrifugation and analyzed to determine the protein ratios. Both collagen and beaded fibrils are present in each region, but the concentration of the beaded fibril is greatest in the posterior cortical volume.