the method involves : ( a ) converting circular sv40 dna to a linear form , ( b ) adding single-stranded homodeoxypolymeric extensions of defined composition and length to the 3 ' ends of one of the dna strands with the enzyme terminal deoxynucleotidyl transferase ( c ) adding complementary homodeoxypolymeric extensions to the other dna strand , ( d ) annealing the two dna molecules to form a circular duplex structure , and ( e ) filling the gaps and sealing nicks in this structure with e. coli dna polymerase and dna ligase to form a covalently closed-circular dna molecule .
C0012854
dna molecules
C0012925
circular dna