Fig. 1. 2-DE and EM analysis of intact plasmid mp1 in vivo replication and recombination intermediates. (A) Autoradiography of a 2-DE gel probed with mp1 DNA. Hybridization signals are explained in (B). Signals of unknown nature are marked with dashed lines and arrowheads. (C) Molecules from regions 1–8 were gently recovered from a gel. Enrichment of accumulated replication and recombination intermediates is shown. (D) One hundred molecules from each fraction were analysed by EM (for details see text). Bar = 0.5 kb. (E) Autoradiography of 2-DE gels of plasmid mp1 digested with the indicated restriction endonucleases. Hybridization patterns are explained schematically.