Patents by Inventor Gerald L. Friesen

Gerald L. Friesen 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).

  • Stable antigenic extracts methods
    Patent number: 4963356
    Abstract: A storage-stable, high potency allergenic extract is prepared by ultrafiltration, retaining fractions having molecular weights of from 1000 to 100,000, and drying the retained fraction to a moisture content of less than one weight percent. The extract can also be pretreated with amylase before ultrafiltration, treated with affinity chromatography before drying, and/or treated with gamma radiation after drying.
    Type: Grant
    Filed: April 20, 1987
    Date of Patent: October 16, 1990
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Emanuel Calenoff, Myron A. Beigler, Gerald L. Friesen, James L. Nichols
  • Stable allergenic extracts and methods
    Patent number: 4716120
    Abstract: A storage-stable, high potency allergenic extract is prepared by ultrafiltration, retaining fractions having molecular weights of from 1000 to 100,000, and treating the solution with gel polymer and/or carbon absorbents. The extract is dried to a moisture content of less than one weight percent water. The purified solution and aqueous reconstituted solutions of the dried extract provide a transparent, colorless solution which has greatly increased stability, remaining transparent and colorless for extended periods.
    Type: Grant
    Filed: November 25, 1985
    Date of Patent: December 29, 1987
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Yuh-Geng Tsay, Myron A. Beigler, Emanuel Calenoff, Gerald L. Friesen, James L. Nichols