Quantitation of Candida albicans polysaccharide using an enzyme-linked immunosorbent assay

The enzyme-linked immunosorbent assay (ELISA) for candida polysaccharide antigen in serum was developed by using double antibody sandwich technique. It was found that serum constituents substantially interfered with the assay. The interference was successfully decreased by heating serum in the presence of EDTA which precipitated interfering serum protein. In addition, candida antigen may be liberated from antibody complexes. The candida polysaccharide antigen in the supernatant was precipitated with ethanol and resuspended in the buffer containing gelatin. A maximum sensitivity of 10 ng/ml was found in the assay using this procedure. This procedure of serum treatment may have potential applications for the detection of other polysaccharide antigens in serum.