Patents by Inventor Stephen A. Duffy

Stephen A. Duffy 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).

  • Efficient large-scale purification of immunoglobulins and derivatives
    Patent number: 5118796
    Abstract: Improved methods for direct purification of product immunoglobulins or their derivatives from large volumes of mammalian cell culture medium include directly subjecting the cell culture medium to cation exchange treatment, so as to adsorb the product but not the contaminants. The eluted product is then recycled, or is applied to anion exchange, for further purification, and optionally subjected to additional steps. The product may be obtained in a form suitable for clinical applications, if desired.
    Type: Grant
    Filed: December 9, 1987
    Date of Patent: June 2, 1992
    Assignee: Centocor, Incorporated
    Inventors: Christopher P. Prior, Stephen A. Duffy, Billy J. Moellering
  • Method to solubilize tissue plasminogen activator
    Patent number: 4898826
    Abstract: Practical amounts of tissue plasminogen activator (tPA) whether secreted by cells naturally producing it or prepared by recombinant means can be solubilized by providing, in aqueous medium at pH 5-14 8 a solubilizing amount of a basic amino acid optionally and preferably, in the presence of a citric acid moiety. The ability to solubilize tPA at concentrations of up to 50 mg is significant as an aid in permitting smaller volumes for purification and permitting single injections of the drug as opposed to intravenous administration.
    Type: Grant
    Filed: December 10, 1987
    Date of Patent: February 6, 1990
    Assignee: Invitron Corporation
    Inventors: Stephen A. Duffy, Christopher P. Prior, Randal W. Scott