Granted Patent
Utility
US 4,851,337 · App. 06/894,566
Extraction of test substances
Inventor:
Carl M. Berke
Patented Case
View Patent ↗
Granted: Jul 25, 1989
Filed: Aug 8, 1986
Inventor
Carl M. Berke
Assignee (at issue)
Hygeia Sciences, 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.