the procedure involves partial digestion of the covalently closed circular plasmid dna with an appropriate restriction endonuclease under conditions which allow accumulation of unit-length linear dna molecules , a controlled digestion of the exposed 5 ' ends with the lambda 5'-exonuclease , and in vivo recircularization of the resulting linear dna in a bacterial host cell .
C0012925
circular
C0012854
dna