intercalating Protocols

Category: Cell Biology and Cell Culture: Flow Cytometry Protocols: DNA Staining Protocols for Flow Cytometry

This protocol describes a method for quantitative measurement of DNA using propidium iodide (PI) staining and flow cytometry. PI stains all double-stranded regions of both DNA and RNA by intercalating between the stacked bases of the double helix. PI cannot penetrate an intact cell membrane; therefore, cells are fixed prior to staining. The ethanol-fixed cells can be stored unstained at 4°C for days, or even weeks, and then stained and analyzed. - [Read Measurement of DNA Content Using Propidium Iodide (PI) Staining of Fixed Whole Cells Protocol]

Category: Nucleic Acid Purification Protocols: DNA Isolation Protocols: DNA Plasmid Preps Protocols

Solutions containing plasmid DNA are adjusted to a density of 1.55 g/ml with solid CsCl.  The intercalating dye, ethidium bromide, which binds differentially to closed circular and linear DNAs, is then added to a concentration of 200 mu;g/ml.  During centrifugation to equilibrium, the closed circular DNA and linear DNAs form bands at different densities. - [Read Purification of Closed Circular DNA by Equilibrium Centrifugation in CsCl-Ethidium Bromide Gradients]