Granted Patent
Utility
US 4,812,396 · App. 07/069,235
Method for detecting enzymatic activity using particle agglutination
Inventors:
Robert A. Ballas, William A. Frey
Patented Case
View Patent ↗
Granted: Mar 14, 1989
Filed: Jul 2, 1987
Inventors
Robert A. Ballas
William A. Frey
Assignee (at issue)
E.I. DU PONT DE NEMOURS AND COMPANY
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.