This is a protocol for plasmid minipreps that does not involve any columns and uses commonly accessible reagents. While it doesn't result in highly pure DNA, it can provide a sufficient quantity of plasmid for sequencing, restriction analysis, preparative digests.Beware of the large amount of RNA that co-purifies with plasmid DNA (it acts as an efficient carrier during the nucleic acid precipitation step). This contamination will make it impossible to determine DNA concentration from standard 280-nm absorbance readings. Credits: I first learned this protocol from the old-style protocols for bacmid purification using the Bak-to-Bac system (Invitrogen). In that system, the large (>50 kb) bacmid molecules were deemed too fragile for the Qiagen spin columns.