Figure 2
From: Production of highly knotted DNA by means of cosmid circularization inside phage capsids
Packaging efficiency and knotting probability of cosmid DNA in P4 phage particles. DNA was extracted from either no cosmid (a), P4cos-8 (b), P4cos-5 (c) and P4cos-3 (d). Samples were loaded in the gel before and after unknotting the DNA with topoisomerase II (lanes 1 and 2, respectivelly, in a-d). Gel electrophoresis were done in 0.6% agarose gels with TBE buffer (1.4 volt/cm × 30 hours) in a and b; and in 0.8% agarose gels with TBE buffer (1.6 volt/cm × 20 hours) in c and d. Lambda DNA digested with HindIII was loaded in lane 0 in b, c, d. Nicked-circular (CCOS) and linear (LCOS) forms of each corresponding cosmid, produced by restriction endonuclease treatment of the supercoiled plasmids, were loaded as markers in lane 3 in b, c, d. Positions of the unknotted nicked-circle (CP4) and the linear form (LP4) of P4 DNA are indicated.