Mussel adhesive enhances the immobilization of human chorionic gonadotrophin to a solid support

Polystyrene microtiter plates coated with 0.30 microgram/ well of the adhesive polyphenolic protein purified from the mussel Aulacomya ater showed enhanced capacity to immobilize antigens such as human chorionic gonadotrophin (hCG). Uncoated and coated wells were activated with different amounts of hCG (from 2 to 500 ng), blocked with bovine serum albumin, and tested with anti-hCG monoclonal antibodies and antimouse IgG conjugated with peroxidase. The reading at 492 nm of the uncoated wells activated with 500 ng of hCG was similar to that obtained with coated wells but using 5 to 10 ng of antigen. The coating procedure also resulted in better sensitivity to detect low concentration of monoclonal antibodies and better signal-to-noise ratio. The capacity of the mussel coating to immobilize hCG, as well as the immunoreactivity of the attached antigen, remained stable for several months.