unstained Protocols

Category: Microscopy Protocols: Optical Microscopy Protocols

The visibility of the faint star light is enormously enhanced against a dark background. This principle is applied in darkfield (also called darkground) microscopy, a simple and popular method for making unstained transparent specimens clearly visible. Such objects often have refractive indices very close in value to that of their surroundings and are difficult to image in conventional brightfield microscopy. - [Read Darkfield Illumination]

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]