helix Protocols

Category: Cell Biology and Cell Culture: Flow Cytometry Protocols

FIXATION and DNA Staining for Cell Cycle Analysis Protocol. This method of DNA staining utilizes ethanol to fix the cells and permeabilize the membrane, which allows the dye (Propidium Iodide) to enter the cells.  Propidium Iodide (PI) is a DNA-binding fluorochrome that intercalates in the double-helix.  Ribonuclease-A is used to eliminate the staining of double-stranded RNA. - [Read FIXATION and DNA Staining for Cell Cycle Analysis]

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]