Hi Em gauden_nt:
Khi plasmid con nguyen ven (nghia la khong bi cat) thi Em se thay tren agarose gel cac "topological forms" khac nhau cua plasmid DNA: multimeric form, supercoiled form, nicked form, linearized form, etc...
Nhu ban Cuong da giai thich: Co le la khi Em lam double-digestion, Em da...