DNA Loading Buffer with TRIS and EDTA (6x) (Blue)

Used for monitoring migration rates during agarose electrophoresis and loading samples onto DNA agarose gels. Coloured loading for easy recognition Reproducible results No need to add dye The DNA Loading Buffer with TRIS and EDTA (6x) (Blue) contains bromophenol blue and xylene cyanol FF as tracking dyes, which are not fluorescent and might otherwise interfere with DNA UV detection. Tracking dye helps to track the progression of gel electrophoresis and the sample loading process in the well. Bromophenol blue (C19H10Br4O5S, Molar mass - 669.96 g/mol) is a weak acid with a light pink to purple colour. The colour of the aqueous solution of bromophenol blue is pH-dependent. Bromophenol blue solution appears yellow at pH 3.0, purple at pH 4.6, and blue at neutral pH. Xylene cyanol FF (C25H27N2NaO6S2, Molar mass - 538.61 gram/mol) is dark green in colour. Both tracking dyes, bromophenol blue and Xylene cyanol FF, are soluble in water and carry net negative charge at neutral or slightly basic pH of the electrophoresis buffer. The net negative charge on Xylene cyanol FF is less than bromophenol blue, resulting in bromophenol blue moving faster than xylene cyanol in agarose gel. The percentage of agarose in gels affects the moving position of bromophenol blue and xylene cyanol FF in the gel. The bromophenol blue and xylene cyanol FF co-migrates with ~350 bp and ~3500 bp DNA fragments in 1% agarose gel respectively. Glycerol provides high density to the solution, so the DNA samples settle at the bottom of the well. It also helps DNA samples to be confined in the well without diffusing out. EDTA binds divalent metal ions and inhibits metal-dependent nucleases. A high concentration of dye provides a very good contrast colour, which is easy to monitor upon electrophoresis progression. However, high dye concentration may partially mask the low abundant co-migrating DNA fragments.