Plasmids are small, circular units of non-genomic DNA that replicate within a cell independently of the chromosomal DNA. Plasmids are most commonly found in bacteria and are used in recombinant DNA research to transfer genes between cells. The Sigma catalog products use overnight, recombinant E. coli cultures as the source of plasmid DNA. Sigma’s GenElute^™ High Performance Plasmid kits provide a rapid, non-hazardous method of isolating high quality plasmid DNA with silica-binding technology and spin column format. Recovered plasmid DNA is in super-coiled form, with no visual evidence of genomic DNA or RNA contamination, and ready for use in applications such as restriction digestion, ligation, sequencing, PCR, and transfection. The PhasePrep^™ BAC DNA kit recovers large-molecular weight plasmids such as Bacterial Artificial Chromosomes in super-coiled form, free of RNA contamination, and with very low levels of endotoxin ready for immediate use in applications such as sequencing, restriction digestion, cloning, and PCR.