Cancer Institute A national cancer institute
designated cancer center

Nelson Teng

Publication Details

  • Optical biosensor assay (OBA).

    Tsay YG, Lin CI, Lee J, Gustafson EK, Appelqvist R, Magginetti P, Norton R, Teng N, Charlton D. Clin Chem. 1991; 37 (9): 1502-5

    We describe a new biosensor immunoassay involving optical diffraction to detect clinically important analytes in human body fluids. A silicon wafer is used as a support for immobilization of antigen or antibody. The protein-coated surface is illuminated through a photo mask to create distinct periodic areas of active and inactive protein. When the surface is incubated with a positive sample, antigen-antibody binding occurs only on the active areas. Upon illumination with a light source such as a laser, the resulting biological diffraction grating diffracts the light. A negative sample does not result in diffraction because no antigen-antibody binding occurs to create the diffraction grating. The presence or absence of a diffraction signal differentiates between positive and negative samples, and the intensity of the signal provides a quantitative measure of the analyte concentration. The technique is demonstrated with a quantitative assay of choriogonadotropin in serum.

    PubMedID: 1893575

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