The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 13, 1996
Filed:
Oct. 06, 1992
Daniel C Stein, Silver Spring, MD (US);
Andrejez S Piekarowicz, Adelphi, MD (US);
Robert T Yuan, Gaithersburg, MD (US);
The University of Maryland, College Park, MD (US);
Abstract
E. coli bacterial strains encoding a restriction gene that degrades methylated DNA, and prevents cloning of genes expressing the methyltransferase responsible for methylation, are mutated by a chemical or physical mutagen, so as to make the restriction enzyme temperature sensitive. Mutant cells are rendered competent, and plasmids expected or known to contain genes encoding methyltransferase enzymes are introduced. The transformants grow at the permissive temperature, where the restriction enzyme system is inactivated due to the mutated gene. Successful clones, expressing a methyltransferase, can be quickly identified by those which grow at the permissive temperature, but not at the non-permissive temperature. The valuable methyltransferases, as well as restriction enzymes associated therewith, can accordingly be recovered in large quantity.