Patents by Inventor Stephen A. Charles

Stephen A. Charles has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4997278
    Abstract: A sensor uses the principle of surface plasmon resonance (SPR) to monitor the progress of the reaction between a sample and a sensitive layer (for example an antibody layer). The layer is applied to the rear surface of a metallic film formed on the surface of an optically transmissive component in the form of a hemicylindrical lens and slide. Collimated light from a source is applied via a lens which focuses the incoming beam to a focus at a point to form a fan-shaped spread of light incident at the point. The light is internally reflected at the point, and emerges from the component to be applied to a dectector array which latter is electronically scanned. The angle of incidence of the light at the point is such as to span that angle which gives rise to surface plasmon resonance, together with a range of angles thereabout so that the progress of the resonant condition, as the reaction between the sample and the sensitive layer proceeds, can be monitored.
    Type: Grant
    Filed: August 16, 1988
    Date of Patent: March 5, 1991
    Assignee: Amersham International PLC
    Inventors: Martin F. Finlan, John E. M. Midgley, Stephen A. Charles, James C. Irlam
  • Patent number: 4745077
    Abstract: The invention concerns assays, such a immunoassays or two-site immunometric assays, performed using a labelled reagent and another reagent bound to magnetically attractable particles which are suspendable but insoluble in a liquid assay medium. After the labelled reagent has become partitioned between the liquid phase and the particles, in proportions which depend on the concentration of an analyte in a sample, the liquid phase is removed. Then the particles are re-suspended in another liquid medium, and the concentration of label observed. The method is particularly suitable for fluorescent and chemiluminescent' label systems, and can conveniently be performed in microtiter plates in which the wells are optically screened from one another, the observations being made from above or below the wells.
    Type: Grant
    Filed: January 17, 1985
    Date of Patent: May 17, 1988
    Assignee: Amersham International plc.
    Inventors: John Holian, John C. Edwards, John K. Martin, Stephen A. Charles