Xylene cyanol can be used as a colour marker to monitor the process of agarose gel electrophoresis and polyacrylamide gel electrophoresis. Bromophenol blue

Bromophenol blue

Bromophenol blue is used as an acid-base indicator, a color marker and a dye.-Acid-base indicator:As an acid-base indicator its useful range lies between pH 3.0 and 4.6...

 and orange G

Orange G

Orange G or orange gelb is a synthetic azo dye used in histology in many staining formulations. It usually comes as a disodium salt. It has the appearance of orange crystals or powder.-Staining:...

can also be used for this purpose.

Migration speed

In 1% agarose gels, Xylene cyanol typically migrates at about the same rate as a 4000 base pair DNA fragment. Xylene cyanol or tracking dye on a 6% polyacrylamide gel migrates at the speed of a 140 base pair DNA fragment. On 20% denaturating (7 M UREA) polyacrylamide PAGE gel electrophoresis Xylene cyanol migrates at about rate of 25 base oligonucleotide. Typically 0.005-0.03% of final concentration of Xylene cyanol is used.