Analysis of the ends of the 90-kb DNA molecule. (a,b) As a control, Stylonychia DNA, isolated by classical methods (Ammermann et al. 1974), was separated by a 0.7% agarose/TBE gel before Bal 31 digestion (U, lane 1) and afterBal 31 digestion [(lane 2) 5 min; (lane 3) 10 min; (lane 4) 20 min; (lane 5) 30 min], stained with ethidium bromide (a), and hybridized withStylonychia telomere oligonucleotides (b). (c,d) Whole cell Stylonychia DNA (lane1) or the isolated 90-kb DNA molecule was separated beforeBal 31 digestion by PFGE (U, lane 1) or at different time points after Bal 31 digestion on a 0.7% agarose/TBE gel (c, ethidium bromide stained) and hybridized withStylonychia telomere oligonucleotides (d). (*) 90-kb DNA molecule.