Abstract: The ccdB gene was introduced, using the Gateway system, to the vector to improve the efficiency of clone construction. The Escherichia coli transfected with vectors containing ccdB could not grow to form clones because the ccdB is toxic to it. Thus, this strategy avoided the false positive clone formation and made the plasmid construct much more convenient. Through comparison of the different strategies of clone construction, this class made students understand more on genetic engineering-related processes such as enzyme digestion, recombination, ligation. This method is suitable not only for the experimental course but also for cloning construction in future research.

Key words: genetic engineering, experimental teaching, cloning construction, ccdB, plasmid