Gel Loading Dye, Purple (6X), no SDS is a pre-mixed loading buffer which contains a combination of two dyes, Dye 1 (pink/red) and Dye 2 (blue).

The red dye serves as the tracking dye for both agarose and non-denaturing polyacrylamide gel electrophoresis. The two dyes separate upon gel electrophoresis; the red band is the major indicator and migrates similarly to Bromophenol Blue on agarose gels. Specifically chosen, this dye does not leave a shadow under UV light. EDTA is also included to chelate magnesium (up to 10 mM) in enzymatic reactions, thereby stopping the reaction. The dye also contains Ficoll®, which creates brighter and tighter bands when compared to glycerol loading dyes.