Patent ID: 7820443

Claim:
A fast method of transforming competent cells prepared from Escherichia coli with a high transformation efficiency consisting of: (a) mixing a plasmid DNA with the competent cells suspending within ionic solution to form a mixture; (b) plating the mixture on a warm selective medium at temperature of 25° C.-45° C. without heat-shock treatment and recovery step which requires adding broth medium; and (c) culturing the mixture on the medium; wherein the high transformation efficiency is over 10 7 transformants/μg DNA, wherein the ionic solution comprises a monovalent cation selected from the group consisting of NH 4+ , Li + , Na + , K + , Rb + , Cs + , Ag + and Co + and a divalent cation selected from the group consisting of Ca 2+ , Mg 2+ , Mn 2+ , Zn 2+ , Cu 2+ , Cd 2+ , Fe 2+ , Sr 2+ and Co 2+ , provided that the ionic solution does not include Ca 2+ alone, and wherein the selective medium is added with an antibiotic selected from the group consisting of ampicillin, kanamycin, chloramphenicol, tetracycline, erythromycin, methotrexate, hygromycin, neomycin and zeocine.