Granted Patent
Utility
US 5,013,446 · App. 07/514,097
Chromatographic gel contactor and process
Inventors:
Yao Li, Brad Yundt
Patented Case
View Patent ↗
Granted: May 7, 1991
Filed: Apr 25, 1990
Inventors
Yao Li
Brad Yundt
Assignee (at issue)
Y.T. Li Engineering, Inc.
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.