Thermo Scientific 6X TriTrack DNA Loading Dye is used to prepare DNA markers and samples for loading on agarose or polyacrylamide gels. It contains three different dyes (bromophenol blue, xylene cyanol FF or orange G) for visual tracking of DNA migration during electrophoresis. The presence of glycerol ensures that the DNA in the ladder and sample forms a layer at the bottom of the well. The EDTA included in the solutions binds divalent metal ions and inhibits metal-dependent nucleases.