5X TD Solution

The 5X TD Solution is composed of Bromophenol Blue, Xylene Cyanol FF, EDTA and Polysucrose. The EDTA in the loading buffer terminates the reactions containing enzymes that require Mg2+ and Ca2+. Polysucrose increases the density of the sample so that it can settle in the well. Addition of one volume of 5X TD Solution to 4 volumes of DNA sample gives color to the sample as well as increases the sample density, which facilitates the loading onto the well. Furthermore, the solution contains two dyes which migrate in the same direction as the nucleic acids, hence serves as an indicator of the electrophoretic progress.