growth of ds-5cl in the presence of 150 mug/ml of tc ( minimum inhibitory concentration is 250 mug/ml in liquid broth ) for a prolonged period of time ( 50-60 generations ) resulted in the disappearance of 28s dna and the appearance of a heterogeneous covalently-closed circular dna sedimenting at about 40-48 s .
C0012854
dna
C0012925
circular dna