DNA Loading Dye
DNA loading dye is a pre-mixed buffer used in gel electrophoresis to prepare DNA samples. It increases sample density so the DNA sinks into the well, provides visible tracking dyes for monitoring migration, and contains buffering agents to preserve the DNA.
Product Description
Key Features and Functions
- Sample Density: Contains high-density agents like glycerol or Ficoll that allow the sample to settle at the bottom of the gel well instead of floating away.
- Visual Tracking: Includes marker dyes (commonly bromophenol blue, xylene cyanol, and orange G) to visually monitor the progress of the electrophoresis run.
- Buffer and Protection: Usually formulated with Tris-HCl (to maintain pH) and EDTA (to chelate magnesium and prevent DNA degradation by nucleases).
Common Tracking Dyes and Migration Rates
In a standard 1% agarose gel, the tracking dyes migrate at predictable base-pair (bp) rates, allowing you to estimate gel run times:
- Xylene cyanol FF: Migrates at approximately 4 kb
- Bromophenol blue: Migrates at approximately 300 – 400 bp
- Orange G: Migrates at approximately 50 bp
