GelRed is a sensitive, stable and environmentally safe fluorescent nucleic acid dyes designed to replace the highly toxic ethidium bromide (EtBr). 6X GelRed Prestain Loading Buffers are gel loading buffers containing density agents, tracking dyes, and GelRed dye. The 6X prestain loading buffer is added to samples in place of gel loading buffer, and eliminates the need to add fluorescent DNA dye to the agarose gel during casting. Download the product protocol on this page for a comparison of prestain, precast, and post-stain protocols for GelRed, and to find the recommended method for your application. For detailed information, please visit the DNA Stain Technology page. Prestain buffer with blue tracking dyes (cat. no. 41009) contains two blue electrophoresis tracking dyes that run at approximately 1.5 kb and 200 bp in a 1% agarose gel. Prestain buffer with orange tracking dye (cat. no. 41010) contains an orange electrophoresis tracking dye that runs at approximately 50 bp in a 1% agarose gel. GelRed and EtBr have virtually the same spectra, so you can directly replace EtBr with GelRed without changing your existing imaging system. In addition, GelRed is far more sensitive than EtBr, which cannot be used in DNA loading buffer to prestain DNA. GelRed is compatible with downstream applications such as sequencing and cloning. GelRed is efficiently removed from DNA by commercial gel extraction kits or by phenol/chloroform extraction and ethanol precipitation. This product is a replacement for catalog no. 31011.