Aureobasidium .beta.-1,3-1,6 glucans and compositions containing such glucans, as well as methods of their preparation. Aureobasidium medium that contains .beta.-1,3-1,6 glucans, particularly medium produced by Aureobasidium strain FERM P-18099. The .beta.-glucans of the present invention have a variety of industrial and commercial uses, including applications in pharmaceutical or medical products or treatments, for the removal or control of environmental or microbiological contaminants, in cosmetics, and in nutritional products and foods.
The ability of a polysaccharide to act as an immunostimulant may be assessed by comparing the degree of binding of a detection reagent, which contains a fluorescence-labeled version of the polysaccharide, with the binding of a reference reagent, which contains a fluorescence-labeled version of a different polysaccharide. The ability of a polysaccharide to act as an immunostimulant may also be assessed by comparing the degree of binding of a detection reagent, which contains a fluorescence-labeled version of the polysaccharide, with the binding of a different type of reference reagent, which contains both the same fluorescence-labeled version of the polysaccharide and an unlabelled version of the same polysaccharide.
A kit for the determination of the ability of a peripheral blood mononuclear cell to bind to a polysaccharide herein provided comprises a detection reagent comprising a fluorescence-labeled immunostimulant polysaccharide; and a reference reagent comprising a fluorescence-labeled material of a polysaccharide different from that used in the fluorescence-labeled immunostimulant polysaccharide, and/or an immunostimulant polysaccharide which is not labeled with any fluorescent material and whose polysaccharide moiety is identical to that included in the fluorescence-labeled immunostimulant polysaccharide. The use of this kit would permit the estimation of the polysaccharide-binding ability of a peripheral blood mononuclear cell in a higher precision of estimation.